Thelma and Louise. A great chick flick, a great road trip flick, a great "sidekick" flick. I guess this makes it a great flick, huh?
The Untouchables. Elliott Ness was lucky to have a sidekick like Malone, the seasoned Irish cop who knew "the Chicago way."
The Sting. Top of mind because I just saw it Friday afternoon. I also picked it because whereas Butch & the Kid were equals, there was more of a pupil/teacher relationship in this movie, with Redford as the sidekick. I suppose you could argue that he was too old to play Johnny Hooker, but then, why argue with any opportunity to see the two coolest guys in the universe on screen together?