IL-2 Sturmovik Combat Sim.......Get it !!!!
 

I'm not particuarly a Flt Sim person, but I dogfighted in a snowstorm over Stalingrad with my brother the other night on a Lan connection and now I'm completely hooked on the game. It makes MS combat flight Sims look decidedly second rate.. .Take care though, you need heavy duty pc to get the full effect of the graphics.