Red Orchestra is indeed great. You really have to hone your skills as a shooter to get any shots, and when you do get the shots they are way more satisfying then, say, Counter-Strike. I also like how the score card doesn't have a kill-to-death ratio. Instead, it's about how many points one acquires. Kills count, but flag captures count more.
Though, in the end, I don't think any FPS will come close to the real thing. Unless they came with adapters that would do bodily damage as you got shot...