Guess I will post mine
Smoothwall with latest fixes
Intel P2 or P3 650 I believe (cant remember, its been awhile since i messed with it)
Genuine intel board
256mb Memory
Dual Intel Pro100 NICs
I also did a keyboard LED mod where i took the LED board from a keyboard and made it into a front panel cover that displays the send and receive status and any errors.
I love smoothwall as it has been running without user intervention for years(except to updated fixes and change certain network configs).
Update to my config:
Removed Keyboard LED Mod
Upgraded to Smoothwall 3.0
Replaced HDD with a 1.8" HDD w/Adapter (like the ones in Zunes and iPods).
I am really happy with the 1.8" HDD, it is pretty much silent. It is way overkill at 60gb, but I got the drive for free and just bought the adapter for like $10 on eBay so I am happy