Greetings to the most esteemed community!
I've been lurking around here ever since coming across LGR's channel and being infected with the idea of reliving my own early computing years. Inevitably, google searches for drivers, specs and workarounds would bring me here, and more often than not would actually help, as opposed to most other sources on the internet. So I figured I might as well (finally) register.
This is not my first build, but it is my first successful one. I began, as most folks here, with a DX4 and a PCI board, but that board just didn't want to work. Now there are two more projects, including an even spicier 486 on a DEC PC LPX+ board, as well as a 386 with an incredibly beautiful (and awfully rare) black/red Compuadd board. Just love the look of that thing, even if its specs are somewhat average. But those are still in progress.
This one is a dual P2 build, which is also a multiple purpose build. Not only it is a DOS/W98 rig, it will also dualboot into W2K (which I have some of the fondest memories of), and it will also serve as my EPROM rig (with proper low level parallel port access, using Willem programmers is a breeze, while anything modern turns it into a nightmare). Finally, I think that retro hardware is beautiful, and putting it behind opaque metal shells is a crime. Hence my choice of case for all my retro builds - Fractal Design Define R6, with side window. This also means I have to colour-match my hardware if possible, adding another layer of difficulty when finding parts.
This is the first picture I have, shortly after installing Windows 98 on the rig, but long after all the fiddling and testing the system was done. I am having trouble locating 50mm coolers for the second CPU, so the ones I have at hand do not quite match in brightness. I've chosen a KingSpec PATA SSD for my hard drive, which is a bold choice, considering there are people that swear by it and people that swear at it. I did want an SSD, and I do think Sandforce is more appropriate controller choice for OSes without Trim support, as opposed to getting a modern SATA SSDs with some adapters. But this is a sutuation where you throw things at a wall and see if it sticks, so I can't tell if it was the right choice until after a couple years of use. Now, back in the day to make a build "hot" (at least in Latvia) you would add a 3COM network card to the mix for good measure. So I did.

Specs so far:
Fractal Design Define R6 case
MSI MS-6120 Motherboard
2 x PII 450 MHz
512 Mb RAM
GF 2 Ti - 64 Mb (to be replaced) - a temporary solution, I'll go for something more period appropriate
ESS 1868F (to be raplaced) - just a sound card most of us have around
3COM 905 CX-TXM
8Gb PATA SSD
Slim Panasonic 24x DVD-RW
Gotek 1.44 Floppy Emulator
Antec Neo 480W PSU
I've finally located the coolers... Also, there is now an elephant in the room, sitting happily atop the case.

The first Voodoo 2 has arrived, an early Creative CT6670 model with nearly black PCB, 12 Mb version. The GeForce is also replaced, now there is a proper Savage 4 in there. Beautiful quality and some exceptional capabilities for Unreal Tournament. I don't remember precisely, but I think it took quite a few generations of GeForces before they started doing S3TC correctly without colour bleed. ESS card was also replaced with a YMF 724, which can make full use of SB-Link on the motherboard for sweet DOS compatibility, while actually being modern enough for windows games to support some 3D effects. Granted, EAX and A3D are better on original hardware, but getting both and DOS compatibility at the same time is worth it.

Specs so far:
Fractal Design Define R6 case
MSI MS-6120 Motherboard
2 x PII 450 MHz
512 Mb RAM
Savage 4 Pro - 16 Mb
Voodoo 2 - 12 Mb
YMF-724 w/SB-Link
3COM 905 CX-TXM
8Gb PATA SSD
Slim Panasonic 24x DVD-RW
Gotek 1.44 Floppy Emulator
Antec Neo 480W PSU
Another Voodoo 2 has arrived (an identical CT6670, black PCB), and while I didn't push them hard yet, I eventually would, so cooling was also needed. Now I don't feel like modding such rare hardware, and this case supports sideways mounting of cards, so I used a Titan cooler solution. It has white fans, however, so I had to change the whole colour scheme. I've also migrated to a larger SSD, one that will have enough space to properly dual boot into W98/W2K.

Final specs:
Fractal Design Define R6 case
MSI MS-6120 Motherboard
2 x PII 450 MHz
512 Mb RAM
Savage 4 Pro - 16 Mb
2 x Voodoo 2 - 12 Mb @ SLI
YMF-724 w/SB-Link
3COM 905 CX-TXM
64Gb PATA SSD
Slim Panasonic 24x DVD-RW
Gotek 1.44 Floppy Emulator
Antec Neo 480W PSU
And this is what it looks like in the dark!

Final thoughts: I still need to add a nice LCD display, run by Arduino, to the disk cage. It will show the logo, specs, and some short Wikipedia-style articles about specific hardware inside. I also may eventually replace the Savage with a 32 Mb model, if I get my hands on a working example. I do have one at hand, but it locks up in 3D mode, and I don't think it is a problem with contacts in the slot, even if it is a bit finicky. So, odds are, it is done for.
I will also eventually try to get my hands on a few HardMPU cards, because reasons (black with a little green LCD kind).
Other than that, this build is finished. It doesn't run Crysis, but it does run Unreal and Homeworld pretty darn well. And Space Quest 5 was a blast, too!
EDIT: updated specs, addes CD/FDD/PSU information