Close the Edge is Yes's most consistent album because every track is absolutely GREAT. Side one, after about eleven minutes, has the best keyboard solo (from Rick Wakeman) you will ever hear in your life. Fragile, from the same era, has a number of short, but irritating, solo tracks, showing a lack of cohesiveness. On the other hand, it has some of their best band tracks and I think Roundabout is their greatest ever song.
The Yes Album is popular with a lot of fans and journalists tend to favour the album, perhaps because the band had perfected their style, while avoiding the later experimentation (which came with Rick Wakeman). Rick Wakeman plays on Yessongs, the live album, and expands the ideas started on The Yes Album.
Tales from Topographic Oceans is much maligned, but I love the album. I would say, however, it is not a good introduction. Relayer, with Patrick Moraz, is again popular, but not my favourite. Drama is fantastic, but not representative, because Jon Anderson is not present, although the tight musicianship is incredible. Going for the One is patchy, but contains the famous percussive Awaken. Yes Tormato is over-produced and rubbish in my opinion.
90125 is their eighties album with Trevor Rabin. Although a Rick Wakman fan, I love the album from start to finish. The Big Generator is messy as is every successive album to date (Open Your Eyes is dire). The exception is Keys to Ascension which combines live and new tracks. Be warned though, some of the live material sounds fresh while other tracks are sanitised. The new tracks are mostly good.
The first two albums Yes and Time and a Word, along with the compilation Yesterdays, are very good, but are for devotees, as the band were still finding their feet.
In short, my advice is go for Close to the Edge and then Fragile. Perhaps, next, The Yes Album, Drama and Going for the One. If you've become a confirmed Yes addict, then Yessongs, Topographic and 90125.