Donkey Kong Country (first game I ever cleared)
The Elder Scrolls IV: Oblivion (spent way to much time with that game)
Gears of War 1 (Most time I've spent on an online game and the best achievement I got in gaming placing within the top 100 and best in Ireland)
Mass Effect 1 (As much as the combat was crappy I loved the story which was better than in 2)
Rome Total War (by far the best in series)