Rushmore.
Then put your little hand in mine
There ain't no hill or mountain we can't climb...
Rushmore.
Groundhog Day++
That movie was filmed at my school. Actually the building shots were at my high school, but since our classrooms were so crappy, IIRC they went across the street to a private school to film the indoor scenes (and the uniforms are from the private school as well). Still haven't seen it though.
While Bill Murray's character was not the central figure, I submit Caddyshack was the funniest movie listed above. His soliloquy about looping for the Dali Lama is an all time scene. And he's got that going for him, which is nice.
I was going to vote for either Groundhog Day or Scrooged, so...Other.
I think of Caddyshack as an ensemble movie too. Ghostbusters & Stripes are pretty much classics.