Before talking about the equipment...
 

Close-up photography is a very technical field; usually, the most obvious problems are not related to composition or artistic considerations but rather to getting sharpness, depth of focus, and good lightning. Pretty similarly to general scientific photography, close-up photographers must first cope with many practical constraints. This is the reason why this section is this long, not because I really believe that technique is really important.

As for myself, the day came that I just realized I could concentrate on lightning, composition and form - not anymore anxiously running to take pictures with the first piece of equipment I could grab from my bag. Now I take time to examine the subject, follow it for as long as I feel before to start taking pictures (unfortunately this approach often results too in bad results...). There still is a lot to learn of course, but I felt that was an important step ahead.

Finally, I do not believe that equipment brand is important. I have listed below my gear by the full name, but I could take my pictures with other tools. So please, do not start silly brand wars that are so common over the Internet...
   
All right, lets go on now...
 
35 mm
Nikon F90X w/MB10 grip A very nice camera that would be vastly improved by adding mirror lockup, a larger viewfinder and vibration reduction (yes, I know I need an F5).
Nikon F4s I wrote the previous comment on the F90x when working on the final version of this page. Two days later I found a clean F4 at a very decent price. So I upgraded to one of the sexiest, best-designed cameras ever made (F5 included, in my opinion!). The F4 is cheap on batteries and can be customized with 3 battery packs, so you carry only the weight you want.
Nikkor 24/2,8 AFD A very good wide lens for general purpose. Can be used for close-ups by mounting it on the PB6 in reversed position (ca. 12x reproduction ratio) but then, beware of diffraction effects!
Nikkor 50/1,8 AF One of the sharpest Nikon lenses... and the cheaper one! Can also be mounted reversed on the PB6 (apx. 5X) with the same diffraction drawback if you use a long extension.
Micro-Nikkor 105/2,8 AFD The most recent from a legendary series, this lens goes to 1:1 by itself. I believe it is a good idea not using f-stops beyond f/11 and its behaviour with added extension is a bit strange due to the internal focusing system. Its real focal length at 1:1 is only 74 mm.
Micro-Nikkor 200/4 AIS Not a great performer at long distances (it suffers from light falloff at the corners) it is excellent in closeup range. It goes to 1:2 at a working distance of ca. 70 cm, thus it is a very good choice for butterflies and other shy insects (at least if you cannot afford the newest version AFD, which reaches 1:1, and weights more than double).
Nikkor 35-70/2,8 AFD A good zoom for general use, professional quality and constant aperture. Handling and operation are quite misleading to me however. Has a "macro" switch and matches very well with the diopter 6T.
Extension tube PK13 Originally intended to allow the Micro-Nikkor 55 AIS to get to 1:1 reproduction ratio, this is a 27,5 mm tube for general use.
Extension tube PN11 Excellent device of 52 mm length, an impressive build quality plus a built-in, rotating tripod socket. I guess that you've read comments about buying third party extension tubes rather than original ones, since there are no lenses inside. I guess that they have never had a PN11 in hand...
PB6 bellows The latest version of the Nikon bellows. Includes focusing rail, built-in lens reversing system, double release cable socket, camera body rotation for vertical framing, double locking lever for manual lens stopdown, and a pretty good build quality. Mine has, however, a drawback in locking the focusing rail: the whole assembly slightly moves upwards. This is not noticed at low magnifications but can be a nightmare in high macro.
Closeup lens 6T Achromatic doublet useful to me only in conjunction the 35-70 in emergency cases, or on the 120 mm for the Pentax 645 (see below).
Firing Cable MC30 Extravagantly expensive device for firing F90x's shutter.
Double release cable AR10 An even more expensive mechanical/electrical hybrid cable release. Its purposes are tripping the F4 and simultaneously stopping down the lens when mounted on the PB6. To make things even cheaper, if you have an F90 you must also buy an MC25 adapter.
BR2A reversing ring This one is used to mount reversed lenses on the bellows. This is to be done at reproduction ratios greater than 1:1 because most asymmetric lenses give better performance that way. The BR2A allows reversing any lens with a 52 mm filter thread such as 50/1,8 and 24/2,8, or... anything else (e.g. Apo-Rodagon), via filter thread adapters.
BR6 auto diaphragm ring Once the lens is reversed you get a nasty followup: you have lost automatic stopdown! This ring allows to get it back... provided you already paid for an AR10 (plus MC25 for F90x).
Nikon Super Coolscan 4000 ED High-end scanner that provides professional image quality at home; an excellent entry point to the digital world for photographers still working with film. Needs however some practice and theoretical knowledge to drive it, as it is very powerful.
   
6X4.5
Pentax 645 with Intenscreen focusing screen Not the latest technological marvel; you cannot change viewfinders, mid-roll film cartridges nor winders, and its handling is strange - to say the less. However this is an excellent camera and has a very good quality range of optics available: there are manual focus lenses, the new autofocus series, and all Pentax 67 lenses that can also be used via an adapter.
Pentax 645 N In this camera almost all 645 bugs have been fixed, and some very good ideas added: autofocus, data imprinting, easy-to-use commands, and full compatibility. And it gets 3 more frames out from each 220 roll!
SMC Pentax 120/4 Macro Following some tests this one is one of the best macro lenses for medium format. Surprisingly, it is one of the cheapest as well.
SMC Pentax 35/3,5

Its 35 mm counterpart would be something around 21mm. This is a fascinating lens that combines very well with the charm of the medium format. You can spend the whole afternoon getting images that just appear.
Extension tubes set The three tubes together get to 100 mm extension (18+32+45). They are nicely built. Actually, given their cost, they should be manufactured by Nikon.
   
Common gear
Gitzo Explorer carbon G2227 My present standard tripod. A gem in terms of handling and versatility, has outcentered basculating column and legs that can be adjusted at every angle. Not especially light (despite use of carbon) it's extremely rigid.
Manfrotto 468RC Ballhead Much cheaper than the legendary Arca Swiss, Kirk and Foba, it works decently and has friction control too.
Manfrotto 055C tripod w/micrometric geared head 410 For indoor and field work if not hiking far away from my car. Heavy and steady, leg handling could be more pleasant however. The geared head is precious in macro as it is self-locking and can be operated in very short steps.
Manfrotto 190SH tripod w/light head 460MG This is a deal among stability, weight and features to carry on my knapsack (I am really lazy...). Happily enough, I do most of my work not far away from my car.
Manfrotto 479-4 monopod w/ball head 308RC The monopod is useful when stalking living, free subjects as in the field, because some setups are much too heavy to continuously hold them by hand. The ball head is the most useful for me, although I rarely lock it.
Kaiser 2-way focusing rail Micrometrically-geared, very useful for precise positioning of the camera viewpoint over two planes, especially if tilting the lens. Can be used with good results on the tripod for outdoors.
Leitz Wetzlar Photar 12.5/2.4 lens Loupe-lens, similar to its counterparts Luminar from Zeiss, Macro-Nikkor, Canon Macrophoto, Minolta and Olympus. These are short-mount lenses derived from microscopy that have not focusing helicoids and are optimized to high reproduction ratios. This Photar is designed for 8-10x at maximum quality. As the mounting thread is RMS, an adapter to M39+1 is necessary to use it in the same way as the Apo-Rodagon. It is of really technical operation because the working distance is extremely short; in practice, the depth of field is not measurable. To make thing even worse, its diaphragm closes down only to 5,6.
Leitz Wetzlar Photar 25/2.5 lens Like the previous one, but has a longer working distance (ca. 20 mm). Thus, it is better suited for 3-D objects than the 12.5 mm. Useful for still subjects in the studio at high reproduction ratios.
Canon 20/3.5 macrophoto lens In the old FD times Canon manufactured two RMS-mounted loupe lenses, this 20/3.5 that is out of stock now, and the 35 (see below) that is still available new i.e. at B&H. Both have a protruding lever in the diaphragm ring, making them quite useable in the field. As this one can reach magnifications up to 10x on bellows, it is more adequate for studio work.
Canon 35/2.8 macrophoto lens This is the field one - I can get nice reproduction ratios (3 to 5x with just a pair of tubes) for small subjects in the field because the working distance is always beyond 30 mm. Can be tilted around 30 degrees, and it covers nicely the 6x4.5 format too.
Rodenstock Apo-Rodagon 50/2.8 enlarging lens Although my first tests with enlarging lenses were disappointing, I changed my mind when purchasing this Apo-Rodagon. Now I use it in reversed position on extension tubes, or bellows. Reproduction ratios that can be obtained are not really high (2 to 6X), because the focal length makes necessary a lot of added extension, and then the diffraction can appear and ruin your image.
Helicoid Zörkendorfer extension tube (Mini-Makro Schnecke) This is a clever extensible extension tube with a built-in triple helicoid, allowing 20 to 60 mm stepless extension. It takes enlarging lenses or anything with an M39 or RMS thread, depending on the adapter. On the camera side, there are adapters for almost any brand too. Manufactured and sold by Zörk Fototechnik Muenchen.
Zörkendorfer tilt tube The natural companion of the latter, this ball joint allows for tilting on all planes the rig of lens plus helicoid tube. Thus, focal plane and perspective correction are possible in 35mm.
2 Metz 30TTL1i flashes They are compact, lightweight, fast-recycling and not really powerful (due to small working distances in macro, you do not need high-powered units). The only thing I dislike is the auto shutting-off feature because it often makes me lose pictures after a long stalking time while they switched off themselves.
1 Metz 40 MZ-3i flash This is the counterpart of the high-end units of original brands; it emulates almost all their features and additionally offers a secondary head. I use it routinely as the main light source.
SCA300/3000 adapters, cables and accessories for Nikon & Pentax Metz is a leader third party flash manufacturer (leadership extends to list prices also). The analogic SCA300 system includes all that I need on cables, adapters and signal splitters. The digital SCA3000 system allows for bidirectional data throughput, but this does not make any sense with off-camera flashes, thus the cable system is not really developed in this system.
Flash brackets This topic has already been dealt with in another section. I am using the Manfrotto bracket and, increasingly, the Novoflex system.
Filters, adapters, diffusers, and other Everything else: filters, adapters, converters, home-made diffusers, coupling rings for stacking lenses...
Film

Since 2000 I am using almost exclusively Fujichrome Velvia and Provia 100F (or Sensia II if Provia is not available). It is frequently said that film is the cheaper part of the story. Although it is true as a general statement, take into account that I only keep around 2 slides per film...

 

REPRODUCTION RATIO AND WORKING DISTANCE FOR ALL SETUPS
RATIO x NOTES
Photar 12,5 mm + PN11 +PK13 1,4,5,8
Photar 12,5 mm + Zörk tube 1,4,5,6,8
Photar 12,5 mm on camera 1,4,5,8
Photar 25 mm + PN11 + PK13 1,4,5
Photar 25 mm + Zörk tube 3,4,5,6
Photar 25 mm on camera 4,5
Canon 20 mm on camera 4,5,8
Canon 20 mm + Zörk tube 4,5,8
Canon 20 mm + PN11+ PK13 4,5,8
Canon 35 mm on camera 3,5,6,8
Canon 35 mm + Zörk tube 3,5,6,8
Canon 35 mm + PN11 + PK13 3,5,6,8
24 mm reversed + PB6 2,7
50 mm reversed + PB6 2,7
105 mm (min. focus dist.) + PB6 2,8
105mm (min. f.)+PN11+ PK13 3
50 mm reversed + PN11+PK13+ Zörk tube 3,4,5,6,8
RATIO x  

 

Specific NOTES:
1 Lightning difficulties due to extremely short working distances.
2 Diaphragm-related diffraction trouble at long extensions.
3 Quite a handy setup for outdoors.
4 To be used with good light levels: it lacks auto diaphragm, you must focus stopped down.
5 Excellent quality results (if referring to 50 mm, referred to the Apo-Rodagon)
6 Tilt abilities can enhance in-focus area distribution by moving the image planes.
7 Reversing ring needed - and double cable release reccommended to keep auto diaphragm.
8 Only stopped down light reading (not relevant when using TTL flash).
   
General NOTES:
Figures above the ratio bars are the working distance (front lens to object, in mm).
The Leitz Photar and the Canon Macrophoto have a 44 mm additional extension included, due to the tube adapter that I use to mount them on M39 thread, plus another one to Nikon mount.
Focusing a moving object at 5x is difficult, but with a loupe lens stopped down, it is absolutely painful. I help on this by using brighter focusing screens on my F4, and stacking on the lens a small, powerful Krypton-bulb pocket light that illuminates the subject field.

Values might not be totally exact, as I measured them through the viewfinder of a F90x, and corrected for the coverage (92%) of the viewfinder. The graphic representation for the Web further reduces precision.