Robert Hughes is a bit of an institution. I remember seeing repeats of his series, Shock of the New, when I was growing up and it was probably the first serious discussion of art that I'd seen on TV (or, given my age, probably anywhere).
You can see most of the full episodes on youtube now. They still hold up. Hughes would inevitable give way to more chummy, down-with-the-kids presenters but I love his rather po-faced aloofness.
Ep 1 of Shock of the New.