By the power of truth, I, while living, have conquered the universe.
If the combat system was slightly refined (I actually don't mind ME1's combat system but I guess you get used to it after 17 playthroughs), the Mako was replaced by the Hammerhead, the Inventory UI was cleaned up, and a greater variety of environments on Uncharted Worlds, then ME1 would be pretty much perfect.
[Edited on 12.14.2012 10:57 AM PST]