1. Fallout New Vegas (PC). Oh, hell yes it was worth it. I played it for 24 hours during the first three days.
2. Call of Duty 4: Game of the Year Edition (PC). Bought it because I enjoyed the normal version so much on PS3, haven't had time to play it that much thanks to Fallout New Vegas though.
3. WH40K: Dawn of War II Chaos Rising. Pretty much the same as above. Enjoyed DoW2 and wanted more, but haven't had time to play much thanks to Fallout New Vegas.
This post might make me seem like a New Vegas addict, but believe me, the craze lasted only the first few days. I'm back to normal now (my gameplay stats on Steam aren't though...).