Hmm.... I've always loved airplanes...too many cool ones to pick for sure...

Vintage:
P-51D ('nuff said)
P-47 (takes a lickin' and keeps on tickin')
Yak-9K (had a BIG m'f'n cannon in the nose...like big enough to slow the plane down)

Modern:
A-10 (GAU-8! W00t! Kill a main battle tank in 2 seconds)
F-22 (supercruise ownz j00)
EF2000 (I dunno if this one's operational yet...but it's chock-full of cool battlefield technology goodness)