What's your absolute best game ending that, once the credits rolled you felt this game was worth every cent you spent and every hour you put in it. For me:
Crackdown 1: an imperfect, perfect game to me and it ends with you finding out you helped the bad guys the entire time and screwed the city over. You were lied to and manipulated the entire game. Should have been a great set-up for part 2. Sadly, 2 sucked
Phantasy Star 2: Great single player campaign, beat Darkside, and it feels like you saved the entire galaxy
Halo 3: Felt epic
Mass Effect 1 and 2: Both were stellar endings IMHO
What's some of yours?