F15 Strike Eagle, Stealth Fighter, Gunship, Strike Fleet....so many great C64 games when I was 13 or 14.
One of the first games you could fight another human pilot was on the C64, I think it was called Saber Ace, or something like that. You could split the screen and fly an F86 against another guy sitting beside you, and is what I consider to be the great great great grandfather of all the games like AH etc that allow flying against another person.
Don't forget Silent Service either, another great. Red Storm Rising and Airborne Ranger, a couple of other favorites.
Microprose sure put out a lot of great stuff back in the day.