Some side questing, Virmire, and Ilos. Also: when players have to decide who to let die, and when AIs have to decide who to let die.
Main story progress with Liara, Feros, and Noveria. Also, the gig economy for adventurers, and very fast romance.
Back from break and starting a new game! Mass Effect's setup, character creation, and intro mission.
Penny Arcade comic mentioned by Greg