I like White on White by Malevich.I remember going to MoMA in the early 90s and entering a gallery with about a dozen large canvasses (maybe 6ftx6ft-ish) that were basically just gessoed with a dark charcoal line, maybe two, painted down the canvass (I don't recall any that were horizontal or diagonal). It was a "series".
I've known many artists, and have quite a bit of original art, but some of what gets celebrated is entirely suspect. Like the duct taped banana a couple or three years ago.