Classic Game Endings Online
Game Revolutions has a project running to collect together some of the finest game endings from the 16- and 8-bit eras. Some of the examples they have for viewing via Flash include Legend of Zelda: Link to the Past, Flashback, Secret of Mana, and Starfox.
I beat Infocom's game Enchanter by (somewhat accidently) exploiting a couple of game bugs. So I didn't have full points at the end. This wasn't ever supposed to happen of course, but there was still a cool ending where the circle of Enchanters expressed vague disappointment in my deeds, saying that "something was missing."