1) The entire "Hyperspace" cue from the climax of ESB is probably my favorite cue.
2) Luke's final attack on Vader in ROTJ
3) The death of Darth Vader with his theme on harp.
4) The throne room Force march from the end of ANH was my fave as a child and remains one of my faves.
5) Orchestral Duel of the Fates opening as the doors open in the Naboo hangar with Darth Maul waiting. Dump all over Episode I all you want, this was one of the coolest music/movie moments in history.
6) Yoda's theme at its most majestic as he floats the X-wing from the swamp to dry land in ESB.
7) The entire finale/end credits suite from ESB.
8) The force fanfare as the Battle of Yavin begins (which, according to Lucas, doesn't exist).
9) The flurry of strings as we reprise Luke's theme in the last movement of the end credits of ANH. This was "remade" nicely in the Episode III closing credits, though I much prefer the original.
10) The Clone Army revealed.