The ending of the game, when Luigi has finally gotten Mario's painting back after a horrifying night. The Prof. decides to use his machine in reverse, sending Mario through a ridiculous course with much comedic hollering. What makes this a Crowning Moment of Heartwarming, however, is Luigi's reaction when Mario bursts out the other end of the machine, fully alive, but with a grate stuck over his head. Luigi opens his mouth in a wide smile, like he can't believe it, cries just a little bit, and lets loose a most heavily relieved laugh. It Makes Sense in Context, and when you've gone through the events Luigi has, overcoming his fear for his brother... That one moment makes it all worthwhile.