me2 had some nice character moments, but its main plot was very stupid with ridiculous reasoning that threw away all appeal of me1. Best elements of me2 (and me3!!) were stories that expanded the stories, already established in the first game (genophage and quarians/geth conflict).
To anyone who thinks ME2 is better, I can only recommend this mighty analysis of the series: https://www.shamusyoung.com/twentysidedtale/?p=27792
Lots of parts, but it highlights all the problems of the second and third games really well.