I was never that much of a Floyd fan, but I always liked Wish You Were Here. I think I first got familiar with it not too long after it came out in 1975. Much later, I came to really appreciate David Gilmour's guitar playing. His solo, along with the demented vocal by Roy Harper, is what makes Have a Cigar so great.
Their rhythm section was less interesting to listen to. I know that Roger Waters is generally regarded as the main creative force of the group, but the rhythm section always sounded lethargic to me.
The other tracks on Wish You Were Here are also intriguing, with the guitar playing a consistent highlight. As with Floyd's other successful works, the tunes and songs are memorable (every piece on the album has a hook and a lyric that will stay with you forever), even if some of the effects are pretty dated.
I never really got into their later big concepts (Animals, The Wall). Actually I think their artistic output, with a few notable exceptions, declined after Wish You Were Here. I'm not sure that, despite their later huge successes (again, Animals and The Wall), they ever again reached the same level as Have a Cigar.