I can never believe the people who warble on about post 88 R.E.M being sell outs and not being as good. The sound changed when the band went major label, but this happens with all bands who are 5 or 6 albums into their career. It's called developing. This collection showcases the most played R.E.M material rather than the best from 88-03. While the majority of the music is excellent, there are many criminal ommisions. Its a nice place to get the hard to find "The Great Beyond" and "All the Right Friends" as well as "Bad Day". I'm not a fan of new track "Animal".
I love R.E.M and they are one of these bands where I just don't think a "Best Of" can ever come near to giving a person a proper taste of them. They are a proper "album" band and its on their non single tracks that you find the real gems. My personal advice would be to listen to all the bands albums (maybe you can leave out Around The Sun) in chronological order - you wont regret it. This isn't a bad place to start your R.E.M obsession and is also handy if you liked a few of their tracks but don't want to commit to getting a few albums.