UFC 4 on PlayStation. Every user review online says it's crap, but then the gaming community is a bunch of anemic virgins with unhealthy anime interests, so it figures they would say that. I found the ground game very confusing and the learning curve for that appears to be vertical rather than steep. Otherwise, I like it. It's a bit "arcade-y" but not in a bad way.
More of a fighting game than an MMA sim (like UFC 3), but I like it for what it is so far. That's my weekend sorted.