i have not seen EP III yet, maybe next weekend,
but so far, yoda whooping arse is way up there... just the way he takes his saber by the force (if you watch close, he doesn't "grab" it, he forces it to his hand), and ZOOOOOM in that high pictched mini-saber sound. he's one vicious little bugger if he's po'd ; )
obi wan dog fighting jenja fett in the asteroid field stands out as pretty cool.
luke fighting vader in jedi was pretty cool.
any scene with the millenium falcon rocks