I also like how the game actually gives you a small section of gameplay after you succeed rather than simply fading to black. While this is partly due to the type of epilogue you get, it also gives you a chance to wind down. You wouldn't believe how annoyed I am by games that go: "Okay, boss down, level over, roll credits." Umm, what? I finished the game for ... credits? Give me something interesting! Something to chew on! Something to come down on or get whipped up about.
Roleplaying games can learn a lot from videogames (and other forms of fiction) in this regard. While plenty of campaigns aren't made with a discernible end in sight and normally just peter out or are cut off suddenly as interest permits, those that do certainly run the risk of ending it too abruptly. Unless everyone had to die to make the ritual happen, there should be at least a short conclusion as they backtrack through the dungeon or say their parting words to each other before riding off into the sunset or they comfort the survivors, or whatever else it could be.
It's also important to avoid the epilogue simply being an opportunity for the players to randomly talk through their characters or to force it to go on for too long. While the GM certainly shouldn't take full control of an epilogue, they should try to flavour it. Let the characters say their final words while walking through the ruined dungeon or during an after-party celebration or over the graves of their lost companions. Give the players the chance to make it poignant. And, of course, if all the players immediately drop out of character post boss fight and simply want to discuss things OOCly than let them do so but don't force it either way. If the OOC chat goes for a few minutes it's probably best to signal the end of the game by packing up your equipment so that they know the game is over rather than allowing a patchy OOC for several minutes brief IC moment OOC for several moments combination.
Don't be afraid, however, to let each player have a bit of narrative control to at least describe the fates of their character if they would prefer or to hear your pronouncements if they like it better. This can be done OOCly even, as a final statement before they head off.
Considering that people generally play in campaigns for far longer than they watch a movie or play a videogame it's important to give the epilogue a sense of 'conclusion' so that they can bask in a game well ended.
So have you ended any games lately? And if so, did you go for an epilogue and how did that work out for you?