I chose Empire (as we teenagers called it 24 years ago
), but truly love all of them. All but TPM are definitely in my all-time top 20 movies.
Star Wars - I still remember the opening crawl, which I thought was cool and immediately engaging. So many movies before and since just have opening credits you kind of half-watch. This had no credits - just story. You took immediate notice. Then a ship under attack. Fine looked good but we'd seen such things, so it was just an interesting start. So now we get the attacking ship ... this thing is big ... um really big ... is this thing ever going to end?!? Wow - that just set everything going ...
Empire - if Star Wars was a classic tale of the rise of a hero of good to defeat evil, then Empire is the classic second act, in which we realize that evil is not defeated, just set back. The large battle happens at the beginning of the movie - again unprecedented before and since. The rest is the small action, big story, glory ... and you really had to have been there for *the* line ...
RotJ - at 17 I was getting a bit old, very busy with so much activity, so I probably only saw Jedi a half-dozen times in '83
The final lightsaber duel between Luke and Vader, *that music* ... it was such a great flick. I had no problem with Ewoks (nor Gungans, for that matter), but was disappointed with Han's role, as comic relief (like C3PO on Geonosis). However, the difficulty of having a main character become sidelined now looks prescient of the roles of non-Jedi in a Jedi world in the prequels.
And ... as I've said elsewhere, if I had to choose favorite overall, it would be AotC. So sue me ... Lucas hasn't raped my childhood