I'm Commander Shepard, and this is my favourite game of this generation.
Mass effect is a third person space RPG, where you assume direct control, if you want, of Commander Shepard, a completely awesome person who just happens to have what it takes to save the entire galaxy from more or less anything you could possibly throw at her (yes, her, deal with it). The game offers a lot of exploration, excellent music, likable characters and also a pretty cool story, bro. Although I personally thing some of the actual combat mechanics were better in the two later games, I think the actual "RPG" part is a lot better in the first of them.
The trilogy may not have ended on the highest of notes but from Mass Effect 1 to 3 the journey was amazing. It tugged at the heart strings, thrusting you into decisions with actual consequences - allowing you to be a goodie two shoes or a bad ass who makes trout happen. The refinements in 2 and 3 may not have been to everyone’s tastes but there's no denying that Mass Effect was a masterpiece out of left field.
All in all, Mass Effect is a game that everyone who like RPGs and sci-fi should try. Also, the Mako rocks and anyone who says otherwise is clearly mentally challenged.