The only critical flaw with Mass Effect is the amount of unrealized potential in a game that gives us the first truly great sci-fi RPG in more than a decade that didn't depend on a franchise property. It has action, it has a compelling story and it even has a little heart. It's the type of game that every RPG fan should play.
If you're tired of games that let you down after the first hundred hours, Disgaea 2: Dark Hero Days is the probably the best thing on the PSP this side of Dissidia: Final Fantasy.