I am currently sharing a HP Deskjet 660Cse, HP ScanJet 6200, Mitsubishi DiamondPro 2070SB, Mitsubishi DiamondPoint NX85 LCD, Microsoft Natural Keyboard Pro and Microsoft Intellimouse Explorer between the machines, I have an APEX KVM switch to make this easier. At my current place I now have 1.1 SDSL being shared amongst the machines as well.  First you will see my semi-functional machines, then afterward I will list all the spare parts I have accumulated in my 10 years of computing fun.

386 - Win 95 OSR2 (This machine hasn't been turned on in a while, I am hoping it is still functional.)
Intel 386 DX 33
32KB Cache
16MB DRAM 80NS
Western Digital WDAC2850 850 MB HD
NEC 4x4 CD-ROM
Cardinal 14.4 Modem
Creative Labs Soundblaster
Hercules Dynamite Pro 1MB DRAM
3Com Etherlink III
Promise EIDEMAX
3.5" 1.44MB Floppy
5.25" 1.2MB Floppy

486 - Win 98 : Second Edition (This machine has more recently been used, but again I am hoping it still works.)
Intel 486 DX4 100
256KB Cache
32MB DRAM 60NS
Quantum 1.6 GB HD
Toshiba 32x CD-ROM
Zoom 28.8 Modem
Creative Labs Soundblaster 16 PNP
Diamond Stealth 64 2MB DRAM VLB
3Com Etherlink III
Promise EIDE2300+ VLB
3.5" 1.44MB Floppy
5.25" 1.2MB Floppy

Pentium - Win 98 : Second Edition and Win XP Pro
Intel Pentium 233 MMX
Abit IT5H
512KB Cache
128MB EDO DRAM 60NS
Quantum 4 GB HD
Quantum 4 GB HD
Adaptec 2940AU PCI
Seagate 2 GB Ultra SCSI HD
Plextor 32x Ultra SCSI CD-ROM
Plextor 4X/12X SCSI CD-R
Creative Labs 2X IDE DVD-ROM
Creative Labs Soundbalster 32 w/ 2MB RAM
Creative Labs Graphics Blaster RIVA TNT 16MB SDRAM
Quadrant International Cinemaster 1.2E DVD Decoder
3Com Fast Etherlink XL
3.5" 1.44MB Floppy

Pentium II - Gone to Jerry
Intel Pentium II 450 MHz
Abit BH6
512KB Cache
192MB SDRAM 8NS CAS2 PC100
IBM 14 GB HD
Pioneer 16X IDE DVD-ROM
Hewlett Packard 8000 4X/4X/16X IDE CD-RW
3Com Fast Etherlink
Creative Labs Soundblaster Live! 5.1
Creative Labs 3D Blaster Annihilator 2 32 MB
Iomega
Zip

Pentium III - Gone to Parents
Intel Pentium III 667 MHz
Intel CA810E
256KB Cache
256MB SDRAM 8NS CAS2 PC133
Western Digital 30 GB HD
Pioneer 16X IDE DVD-ROM

Pentium 4 - Win XP Pro
Intel Pentium 4 1.6 GHz
Abit BD7
512KB Cache
512MB DDR SDRAM  PC2100
Seagate 4.24 GB Ultra2 Wide SCSI HD
Seagate 8.54 GB Ultra160 Wide SCSI HD
Seagate 17.0 GB Ultra160 Wide SCSI HD
Plextor 40x Ultra Wide SCSI CD-ROM
Plextor 8X/20X SCSI CD-R
Pioneer 10X SCSI DVD-ROM
3Com Fast Etherlink XL
Creative Labs Sound Blaster Audigy
Abit Siluro 4400 geForce 4 128 MB
Adaptec 29160 PCI
Iomega Zip SCSI
Lots of fans, current count I think is 14, still runs 10 degrees above ambient temperature.

Spare Parts - My list was so out of date I just removed it and will update some day.