-The ritual decision is one of the great RPG moments imo.
-Then the battle where you can call on your allies you have gathered.
-Then round it all off with the classic celebration scene where you say goodbye to everyone.
-Then the slides showing what happened to the main characters.
I thought it was an exceptional ending, with all loose ends tied up(except one that was dangled in front of us to great effect

) and a very satisfying conclusion imo....bought to you from the people behind Mass Effect 3!