My favorite fighter plane of all time would be the Japanese Zero. That's a pretty awesome plane. My favorite bomber would be the American B-17 Flying Fortress.
Geez....I'd have to say the classic lines and curves of the A-6 have always been atractive with the F-4 Phantom and all of its sleek power in a close second.
Cheers
Its already been on the fav list, but most defiantly the A-10 "Wart Hog" To all you tankers sorry, but it cuts through armor like a knife through hot butter.