This is hard to pick just one so i'll go by each war.
WW 1 Fokker Dr 1, the Baron did pretty good with it.
WW 11 Curtiss P-40"flying tiger" edition , It just looks good
Korea MiG-17, I would have defected just to fly one of these. Probably the most beautiful aircraft made.
Viet Nam McDonnel F4-J. The best looking US aircraft.
Modern era McDonnel/Douglass F/A-18 Hornet. Wouldn't you choose this one?