I try and avoid realistic games, but I have bought one or two realistic shooters. The most recent being OFP:DR. I'd say it was the most realistic shooter I've played.
I was having this discussion with somebody the other day, and they decided to try telling me that BF was realistic, mainly BF:BC.
To be fair, at this moment in time not many realitsic games come to mind. As I said, I tend to avoid them as if I wanted to play something extremely realistic I'd go outside.
Oh, also, Forza 3 has a very realistic feel to it.