I'm not platform specific, but I would to RP a fighter pilot or a Tank Commander, a Submarine XO or PT Boat captain.  I'm not necessarily looking for the slog of infantry combat, but I think there's good RP as a 'Commando/Para/SBS/etc.' or sniper too.

GURPS? FATE? Feng-Shui?

Alternatively, I would love a go as a Y-Wing or a TIE pilot; a Mech captain or SF3d trooper.  DreamPod 9? Legionarre?  Alt-WWII mecha on the Eastern Front or the Ardennes?

Let's do it.