I believe Kingdom Hearts is the best game of all time (check the username, haha). It's got everything that makes a great game I think; wonderful story, super talented voice actors, great balance of action and puzzles, side-quests for the completionists. And of course epic boss battles in tons of Disney universes! It makes you nostalgia the FIRST time you play it haha. The rest of the series doesn't live up to the standard this game set though. I think the best series of games is between the Metal Gear series and the Grand Theft Auto series. Though the Team Ico works (Ico, Shadow of the Colossus) might be in contention when their latest one comes out, those games just take the art form to a whole new level.