Animals is a pretty perfectly considered masterpiece, IMO. Love how the two bookend tracks ground the cynicism of the rest of the album. Went with that.
I find The Wall too overbearing, heavy-handed and full of itself in a very Roger Waters kind of way-- my pick for most overrated, as I rarely find myself interested in it, although it is well done. Dark Side of the Moon is incredible and universally accessible but isn't quite perfect-- I actually am not a fan of the on-the-nose transitions (like the alarm clock/coins at the beginning of Time/Money) and effects (On The Run sounds dated and uninteresting to me) on that album (and of course, Money sounds out of place). Wish You Were Here is a warm, satisfying, and sentimental album but it also feels like it's missing a little something. I think Piper at the Gates of Dawn is great but a little rough around the edges, and Meddle kind of only relies on about half of the tracks being great. These aren't actual complaints, just reservations that keep them from being the best for me.
Love Pink Floyd and think they're brilliant, but just short of my actual favorite bands. If I'm nitpicking, Waters' writing style has always felt a tad overly self-serious to me compared to some of his peak contemporaries like Lou Reed, John Lennon, Brian Eno, or Bob Dylan, who I feel have ideas and a sense of creativity that seems a little more natural/expressive and like they're organically flowing out of them rather than this meticulously prepared/perfectionist/trying to be ambitious thing that Pink Floyd usually have going for them.