I don't see why you guys buy these games day one. ME1 and 2 have been my defining games of the gen. I bought both at $20.
ME1 is more experimental, has a lot more options for your characters... but until you get later in the game... ME1 freaking sucks. You can't aim straight, your biotics don't do crap, and you have very very crap health. You get to the end game, or at least have maxed a few of your abilities, and the game gets good if not great.
ME2 takes away a lot of the most flawed portions of ME1, and makes other portions worse, while still being the more competent game.
Speaking as someone who has put probably 500-600 hours into each. Neither has a good story. No matter how you play it. I'll buy ME3 at $20-30.
I bet it will be a great game too. Hell it already sounds like it's taking that slightly experimental nature of ME1, and putting it in the ME2 shell. Which I don't know about you guys (I'm a ME expert) sounds pretty damn good to me.