ME1 has the better story, but is far from a good experience to play on 360 (it's perfect on PC, by comparison). ME2 has the worse story (which is simplistic and very easy to follow, and does not really require any knowledge of ME1 to understand), but is far, far better constructed, making it play brilliantly on 360 and PC.
As to whether a comic can do justice to the first game: I doubt it, but I'm open to being convinced that it provides more than enough to get you going.
Personally, with what I know at the moment, I'd play 1 & 2 on PC first if I wanted the full experience and money was not an issue (all the DLC adds up pretty quickly, after all); I'd only choose 360 if I had no gaming PC and I desperately wanted to play both games. If I just wanted to play ME2 and ME1 didn't interest me (which is not my preference), I'd probably plump for the PS3 version as it gives everything required to get going and also includes all the existing DLC, which is pretty damn good, especially if you wait a little for the price to drop (which will pretty much make it a bargain).
So, for the full experience, go for PC. For a drop-in-and-play experience (i.e.: not caring too much about ME1), go for PS3. It seems 360 is second in both categories, but last in neither.











