I was pretty displeased with Mass Effect 2. The story and combat were both great, but so much of what made the game incredible; the exploration, the deep character customization, the interesting squad members, was just neutered. You went from 12-15 different talent choices in Mass Effect to just 4 (5 with specialization) in Mass Effect 2. Then they completely removed advanced class paths (Commando, Bastion, etc.) from the series. I loved Mass Effect 2, but I don't think it can be argued that it's as deep as the first game was.