ME1 was a rough diamond. It had loads of potential and had loads of issues. The writing was strong and some points, painful at others. It moments of brilliant pacing and drama, and moments of bizarrely contrived ideas, but I enjoyed it and was interested in a sequal.
I wouldn't say ME2 was near perfect, there are plenty of things I don't like (tedious planet scanning, uninspired safety net boss battle, Liari T'soni [but then I never liked her], backpeddling on the homosexual romance), but I will say that it was solid, the writing was great, the pacing was strong and it built to a brilliant, emotional climax. It's a wonderful game that missed the mark just slightly in my opinion, and the twisting multiple storylines that span games are definitely a great achievement.