1) Mr. Holland's Opus - gets me EVERY time.
2) Angels in America - beginning with Harper's monologue in the plane through the end.
3) Dead Poets Society - from Wikipedia:
"The film concludes with the boys, led by the previously very timid Todd Anderson, standing on their desks — in front of Mr. Nolan, in open defiance — calling to Mr. Keating, "O Captain! My Captain!" to show him that his messages have been understood and appreciated. With tears in his eyes, Keating says "Thank you, boys. Thank you," and the film ends on a high, but uncertain note, with the viewer wondering what would become of Keating and the boys who supported him."
"High time we made a stand and shook up the views of the common man" - Tears for Fears