Yes

The Yes Album, Relayer & Going for the One.
After that, they just went downwards from Tormato.
Their 1980 release 'drama' is worth checking out though. But i would avoid the rest.
And oh, check out relayer first! It's slowly becoming my favorite Yes album.(Close to the Edge is still on top though)
 
Purists will be pained to know that I find the 90125 album fantastic.

Nothing wrong with that! I love 90125. The next album Big Generator, is my second favorite. Tales From Topographic being my absolute favorite. Big Generator had Trevor Rabin conciously bring back some of the 70's melodic guitar, but still kept the heavy rhythm.
And Yes, Drama is a great album. The keyboard, guitar, and bass interplay in the middle of Machine Messiah is fantastic. Squire gets the bass galloping along in that song. Some of the material that's on Drama was material Jon and Rick wrote before they had a hissy-fit and quit the band. I have a bootleg (got in back in '87) cassette of those studio outtakes. Now some of it made it onto the remastered Drama album. I think Trevor Horn reworked some of the Anderson songs, and made them better. He's not as good as the cosmic/strange JA, but reworking those songs made them work for the album direction. Tempus Fugit and Does It Really Happen are strong songs as well.
Pretty much as Genesis, the majority will say any Yes album from '71-'77 is the band in their prime. Tormato ('78) had some good songs, such as Silent Wings of Freedom, Onward, Release-Release, and Future Times. But, the band members were all kind of losing enthusiasm in Jon's lyrics, and band direction, so the album had some half-ass, lackluster songs.
I think the '93 album Talk is a strong album. There's actually a great 17+ minute song called Endless Dream. Trevor's got some slide-like guitar in the song that's reminiscent of Relayer, and CTTE albums.
 
Also, I know this has been mentioned before, but if you like Yes you should consider checking out Jon Anderson's solo records, especially Olias of Sunhillow.
 
Yeah, I remember you suggesting that, and me responding in agreement. So I'll again agree with you! Olias is so atmospheric, and "cinematic" in a way. Out of all the Yes solo albums that each member decided to do for the fist time in '75, Jon's was the best. Olias shows how much of the Yes sound comes from him. Chris Squire's solo album Fish Out Of Water is good. Patrick Moraz, Alan White, and Bill Bruford help out on that one.
I have a few Moraz albums, you like him? I feel that Rick Wakeman is the best of the best in keyboardists, but Patrick is almost as good. Highly underrated. I like Steve Howe's solo albums, but I wish he wouldn't sing! Back up vocals in Yes, it works, but Steve as lead vocalist.....ummm, no.
 
Yes shits over Rush any day of the week.

Anyways here are my favorite albums in order:

1) CttE
2) ToTO
3) Relayer
4) Fragile
5) 90125
6) The Yes Album
7) Going for the One
8) Tormato
9) Big Gen


Everything else it pretty much shit except for a few scattered tracks here and there.