wow that's a toughie. You sorted the machines by year, with no other criteria, like if they are to be systems the common man would use, or cutting edge machines for the respective year.
For example, in 1993 lots of people were still using 386 machines - cheap DX33 or DX40's, or even older DX25 machines that they got new back when they were cutting edge. Some upgraded the CPU to a 486 (like the 40MHz cyrix or TI), others used the machine as it is. Quite a few new machines in 1993 were 486 builds - in fact I believe those were the bulk of all PC sales. 1993 saw the launch of the P5 Pentium (Socket 4) - the wealthy would have bought that, either in 60 or 66MHz flavour.
I think for 1993 the most representative build would be:
66MHz 486DX
VLB motherboard
4-8MB of ram
250-500MB HDD
1x 3.5" FDD + 1x 5.25" FDD
VLB HDD controller
VLB Video card (cirrus logic or trident were most common, and the VLB CL cards are fantastic)
Your choice of sound card - either creative, media vision or gravis, but I think creative cards and clones were most common.
I think your 1994 machine should be a Pentium build. It was all the rage in magazines back then, tough it was still very expensive. The avarage Joe would still be using a 486, probably the same 66Mhz machine described above. Some would still stick to a 386 or slower 33MHz ISA only 486, but some (lucky few) could afford a pentium. Most new machines sold were 66, 80 or 100MHz 486. Here's how I see a 1994 build:
66MHz Pentium P5
PCI or PCI+VLB combo socket 4 board
16MB of ram
250-500MB HDD
1x 3.5" FDD
1x CD-ROM Drive
on board HDD controller
PCI video card - preferably a Matrox Millennium or S3 Vision (I'd go for the S3 for it's great dos compatibility).
Sound needs to be something fancy - preferably with build-in wavetable, like a Yamaha SW20PC, or a GUS, or a Creative card + wavetable module.
* socket 5 machines were available in 1994 (just launched), but they only really saw any significant market penetration in 1995.
1995 - P54 Pentium. Back in 1994 intel launched the socket 5 platform to replace the socket 4 pentium P5. The fastest CPU available for that platform was the 133MHz Pentium (non-MMX). The Pentium PRO launched that same year, aimed at professionals and the server market, but they were extremely expensive and adoption rate was low at launch.
1996 - Year of the multimedia and 3D graphics PC. Intel was tlking about MMX and the pentium PRO was starting to take off. This build (in my view) should be a socket 7 machine with some 3D capabilities.
200MHz pentium
Socket 7 mainboard
32MB of ram
500-800MB HDD
FDD, CD-ROM
sound card of your choice - preferably something with a wavetable sinth
PCI video card
3DFX Voodoo 1