Robert Heinlein, left, with L. Sprague de Camp, center, and Isaac Asimov in 1944.
When I was a teenager, Isaac Asimov probably was my favorite writer, and Arthur C. Clarke was my favorite science fiction writer. So for me the Big Three was in effect a Big Two.
But I was a science fiction fan, so I read plenty of Heinlein, although I never got around to reading pretty much every word like some of my friends. Robert Anton Wilson was a big Heinlein fan; in this interview, he said, "Heinlein has been an idol to me for more than 20 years. He can do no wrong, no matter how much he loves wars and hates pacifists."
Heinlein has always been controversial; still, I was started to read this Cory Doctorow passage in which Doctorow attempts to select the most offensive Heinlein book:
Which brings me to Farnham’s Freehold, a strong contender for the most offensive of all of Heinlein’s novels. Published in 1964, it features a nuclear holocaust and a post-apocalyptic world in which African-Americans are ascendant and have enslaved the remaining white people, whom they occasionally eat. Incredibly, this does not automatically qualify Farnham’s Freehold for Heinlein’s Most Offensive prize, because his typewriter also produced books like Sixth Column (America under the cruel dominion of the Yellow Peril), Friday (sure, rape’s bad, but hey, relax and enjoy it, why don’t you?), and I Will Fear No Evil (there are no words).
Source (there's more criticism of Farnham's Freehold.)
Of the books Doctorow mentions, I've only read Friday; I remember thinking the rape scene was weird, but I didn't have a strong opinion of the book one way or the other.
I do wish Cory had said which Heinlein books he thought were the best, or perhaps the least offensive. I really liked The Moon Is a Harsh Mistress, Double Star and Stranger in a Strange Land. I liked Double Star, too. Time Enough for Love was long and weird but had its moments for me. I didn't like Starship Troopers or Glory Road.