I get this feeling from time to time. I just whacked on Murmur and it really was a groundbreaking album for its time. They then went on to make 10 more brilliant albums over 15 years. The first one that dropped below "very good" was probably Reveal in 2001. Being so consistently good over that period of time, and thinking of all the bands they influenced ... I think they win for me.
Educated disapproval only please. I.E. you actually have to have heard most or all their albums with an open mind. Your parents liking Automatic For The People is not a valid reason for REM hatred.