Killing Kai Leng in Mass Effect 3 was a pretty great moment. Fighting the Ebony Warrior in Skyrim. Finishing Ratchet and Clank Future: Tools of Destruction takes the cake for me. That game is my favorite game of all time, and finishing it for the first time was amazing. After who knows how many corrupted save files, 2 game disks, and1 PS3 later I finished it, 100%. That was one of the best moments ever for me.