Look harder.
REM has had two great 90s albums, in New Adventures and Automatic. They should be up there I think, though I've never seen any REM fans on this board before...
I might sound like an old crone but owning every REM album, there are only two 90s albums that I listen to and those are the ones you mentioned.
I think Out Of Time is a bit flimsy (Losing My Religion, Shiny Happy People are great; the rest is kinda self-derivative). Monster is terrible and I stand by that. There are a lot of pretentious views on that album, but I think it is embarrassing. Peter Buck uses about 4 chords on that album; for a decent guitarist his playing on that is atrocious. The lyrics are awful and Stipe had a definite off year when recording that.
Up is ok; not as bad as I first thought. There are some good songs on it, but it is far too long and way too synth based. Reveal is also a nice listen.
Around The Sun is an absolute disgrace for REM - it is far and away the worst album they have ever done. Derivative, soppy rubbish with boring lyrics, stolen melodies (from themselves) and uninspired playing (is Buck there at all?)
I listen to the entire 80s catalogue quite often and its energy and melody takes away from the fact that the were very forumulaic on the early albums (Jangly guitar, lively bass).
As for Radiohead, I own The Bends and have never gotten into it. It's the only album I own that I really can't be bothered listening to. I'm sure it's great, but I find REM far more accessible.