Ooo. Got me researching on "only novel"s. (I skipped the "controversy" part to make it easier, although I agree that's a fascinating element)
The bulk seem to be 18th and 19th century works by people no one's heard of. (Trust me) Nothing else to do back then, I guess.
But among the might've heard of and obvious:
Oliver Goldsmith - Stoops to Conquer
Muriel Rukeyser - Savage Coast (Mostly known as a poet)
Plath- Bell Jar (I feel there are a probably host of single novels by poets)
Lee- Mockingbird
Katherine Anne Porter - Ship of Fools
Chekhov- The Shooting Party
Giuseppe Tomasi di Lampedusa - The Leopard (yes, the one turned into Visconti's film)
Margaret Mitchell - Gone w Wind
Does Catcher in the Rye count?
Need more.
And here's a whole article about celebrities who have written a novel:
https://www.buzzfeed.com/briangalind...jdv#.pwXE5oWaq