IL2/46. I have never had a game that has given me so many uninterrupted years of enjoyment. With the exception of my one year deployment I should say. Even then, I had a friend in HQ who had a laptop and I talked him into letting me install IL2 on it. I didn't get to play it very much but he liked it so much (even playing with just the keyboard and mouse!) that he even ordered Forgotten Battles! How about that!

Playing Il2 in
the middle of a combat zone!
Inside our base of course...