Ayn Rand: mostly confused gibberish - I can spot a Randian narrative a mile away, it rapidly departs from any known reality, leaving plot holes a mile wide, and lots of ridiculous pseudo science. The protagonist makes a lot of windy speeches, the false protagonist foil is suitably awed.
Michael Crichton might be the exception; although his stuff never impressed me overmuch he did manage to avoid the usual cliches.
The irony with the more decent Randist authors (Frank Miller is another), is that their heros are ultimately self sacrificing, which is the opposite of the Randist opportunistic stereotype.
L. Ron Hubbard is just as bad, juvenile at best.
I agree with Ayn Rand being gar-bitch. I also put forth Sam Beckett, Jim Joyce, Chuck Bukowski, and Chuck Palahniuk as super duper overrated heroes. The most overrated of all-time: Kurt Vonnegut.