This is really the only RPG that I've played on any of the consoles in the last few years (couldn't get into Dragon Age). I've never been big into sci-fi stories (always preferred the medieval times), and I've fallen out of love with the time consuming leveling up RPGs. This series really just works so well that none of that mattered.
ME2 had such a great balance of action, cut-scenes, and core story telling. The original Mass Effect really tells the whole story best of why you are here and what's going on - not to mention the Reaper's voice in ME1 just sounded so cool. However, if you've played ME2, I think it's hard to play ME1 just because of the action and pacing being distinctly different. I'd still recommend playing ME1, though.
I loved the introduction to ME2 as it definitely sucked me into playing the game right away. It's been rare for almost any game that I've played where I just felt such a great desire to keep playing to figure out what the heck is happening and what will happen next. Of course, if I hadn't played ME1, I'm not sure that it would have had the same effect.
Yeah, I'm excited.