You can probably guess from the forum title that I wasn't a fan of ME2. I was hugely disappointed with it. The presentation and story of ME1 was absolutely fantastic and ME2 just didn't come close for me. ME2 disappointed me so much (along with pretty much everything Bioware has released since ME1) that I waited until ME3 was 50% off before buying it. I just started playing it a few days ago and I've only done the first couple missions, but it seems a lot better. The atmosphere is way more interesting and I'm actually feeling that sense of urgency that ME1 provoked in me.
I do, however, still have a serious issue with the franchise. After beating the ridiculous giant robot head at the end of ME2 and realizing that 75% of the game revolved around recruiting half a dozen or so characters which were thrown in out of nowhere with literally no interest or links to the overall story, I was annoyed. The other 25% of the game revolved around the introduction and subsequent elimination of a brand new antagonist who was building a giant robot-human hybrid...*sigh*. Anyways, the character writing was so good in ME2 that the game at least had some endearing qualities, and I really grew to like the cast.
Coming in to ME3, which seems like a better game overall, I can't help but feel even MORE disappointed in ME2. I endured the goof story and spent all that time recruiting and nurturing a crack team of specialists, worked hard to make sure they all survived, and then it turns out that they barely even play a part in ME3? Bioware lauded itself on how impactful the consequences of your choices would be, but it turns out this isn't really the case at all.
My concern that ME2 was a completely throw-away story in the overall ME universe seems to be confirmed. You could quite literally skip the entire game and go from ME1 to ME3 and miss very, very little.