Yes

Definately "close to the edge" is the best, and in my opinion the song "close to the edge" is also their best.

"I get upppp, I get do-ow-own" *cue organ*

If you like that you gotta like King Crimson, "larks tongues in aspic" and "in the court of the crimson king", which is album their best is pretty debatable.
 
Weird, I just picked up "Close to the Edge" about two weeks ago, and was blown away by it! It's pretty much my favorite CD at this point in time, there is so much going on in it...Some of it is pretty dark, and almost metal-like, while some of it is happy, but still cool, and very unusual. The whole album has a quirky sense of melody, and interesting rhythms. And it's a very visual album, I can see strange mind images when I listen, quite a trip! Check it out, especially the title track.
 
Close to the Edge
Tormato
Going for the One

I disagree with the Genesis comparison. They didn't completely sell out, try to add horns and Motown influences and generally suck cock. 90125 and Big Generator are definitely slick and pollished like most 80's music but it still kicks ass!
 
Get Yessongs. It's pretty much the best live album I've ever heard. 2 cds longs (4 vinyl? I don't remember), they play all of Close to the Edge. I don't know why, but I love the live version better. Get it!

F
 
I've See All Good People
Roundabout

I've listened to Yes since I was little.. my dad is a huuuuge Yes-fan and when I was a little boy i used to do everything my dad did, and that included listening to Yes