System:

Macbook Pro
2.5 core duo
4 gigs ram
Windows XP (free hacked version)
Ping: about 230-250

I occasionally have lag issues, but it's a ping issue, never a system. Overall, the game runs extremely smooth.

UO SP: AurelianoBuendia
UO Pac: Magus, Running Fool
DF: Arjuna