They'd Rather Be Right (1954) by Mark Clifton and Frank Riley is notorious as the worst novel to ever win a Hugo. It's also probably the least read. I managed to track down a copy, and it's not very good at all.
It's all about a god-like computer that can make you perfect in every way, including immortality, but only if you give up your prejudices and accept that it is right and you are wrong. I don't like the theme (which brings echoes of every cult to mind) and the story isn't very interesting.
I've read all the Hugo winning novels from the first (The Demolished Man) to 1981 (The Snow Queen) and didn't dislike any of them. After skipping a couple of years, I didn't dislike any until I got to Ender's Game, which I thought was overrated at best. I have read very few since then, although I loved the Kim Stanley Robinson Mars trilogy, Jonathan Strange & Mr Norrell (sorry, SilentRoamer), and The Three-Body Problem. I'd agree that The Doomsday Book is overrated.
Had not looked it up for a long time , in 1954, there was
Caves of Steel by Asimov,
I Am Legend by Richard Matheson ,
Martian's Go Home by Fred Brown,
A Mirror for Observers by Edgar Panborn.
(Pangborn, boy, there is an unjustly unknown fine SF writer.)
Gad! It's a bit boggling that
They'd Rather be Right is trumped any of these novels.
I am Legend is the best novel that Matheson ever wrote (with three is it four? movies , only one of which approximated the novel, the others are wrong headed rejigging a great story.)
Caves of Steel is Asimov's best ROBOT novel , people should read it.
A Mirror for Observers occurs on best SF of all time lists , I am sure most , these days, have never heard of it!!
You know , on that list, the one novel that sticks with me all the time is
Martians Go Home. This is the damnedest crazy story about an alien invasion I know of. The Martians invade , in a teleportation kind of way, all they do is annoy everyone! They vanish as mysteriously as came. I have never read another SF novel like this , goofy and funny it is a gem.
Boy that Hugo was a sows ear among a pile of pearls.