I can think of a few - H.L. Mencken and George Jean Nathan (theater critic) from the 1920s-1930s. Susan Sontag (a beanie-headed liberal but wrote good essays about science fiction and camp.) Pauline Kael was an entertaining movie critic. I agree that most aren't worth reading.
G.B. Shaw also was a critic--but clearly what he created was more enduring (and endearing) than his critiques.