Scarface. The plot wasn't awful ... the clothes, crap 80s music montages, and Pacino's rough Ricky Ricardo imitation just did it in.
Top Gun. Homoerotic chick flick dressed up as a guys-guy movie.
Napoleon Dynamite. I don't get it. At all.
Rocky Horror Picture Show. I don't understand how anybody thinks this fruitcake freakshow is watchable. The sheer number of people that seem to actually like this movie is inexplicable.
Taxi Driver. Overrated. I expected Travis Bickle to be a more compelling psychotic than he was. Lecter, Bateman, Joker and Chigurh put him away.
Avatar. A spectacularly rendered turd.
The Big Lebowski. "Hate" is too strong a word. It had funny moments, "The Dude" is funny enough, and I can watch it from time-to-time ... but, as much as people rave about it, it wasn't nearly as legendary as I anticipated.
Anything with that dipstick from Borat. What an ***.
War of the Roses. I remember people thinking this was funny. Finally watched it last year. Intolerable.
I'm sure I'll think of others.
SnakeDoc