I've got Mafia 1, didn't like it at all.
I'm really excited about BF3, but I'm not sure my system is beefy enough to handle it.
So far, my serious considerations after watching gameplay and reading reviews are Dragon Age: Origins, and The Witcher 2. A nice RPG wouldn't be bad.
Also, I guess I should note that I love turn-based RPGs and whatnot.
Mafia 2 I thought was a rather enjoyable game for what it did. Had more potential than what it delivered, but it was an entertaining game nonetheless.
The Witcher 2 seems nice so far, I've not really had a lot of time with it but it's nice, definitely a lot more playable than the first.
I'll also say I really enjoyed DA:O and several of its DLCs myself. I believe I spent about 60-70 hours on my playthrough, it's pretty meaty.