For the legit lols and Vegeta's epic entrance (which made the lols greater once he was screaming in the original dub): Movie 7
For the fights and a strong Gohan: Movie 10
For the epic entrance and finish (Gohan's Japanese lines): Movie 9
Movie 1 is a contender for Piccolo's entrance in Japanese though, movie 4 for the cool setting, Piccolo's shine and ofc SSJ, movie 12 for "But Vegeta, you're already dead" and that whole convo.
If you count Hatchyak that easily replaces Movie 9 in my favourite 3 though.
Movie 8 is the movie that had it going and then notoriously fucked up.