I love Lost Horizon as well! Not in the same tub-o'-crap category as Mame. For me...
Tub-o'-crap/Barely Watchable/Please Stop the Music:
Mame
Man of La Mancha
A Little Night Music (although I've made it all the way through a couple of times)
Song of Norway
A Chorus Line
The Wiz
Annie
Phantom of the Opera
Goodbye, Mr. Chips (O'Toole)
Guilty Pleasures/Campy Treasures:
Lost Horizon
The Apple
Can't Stop the Music
The Little Prince
Sextette
Pufnstuf
Father Frost (Russia)
Sgt. Pepper's Lonely Hearts Club Band
Phantom of the Paradise
"Jaws is the Citizen Kane of movies."
blocked: logan2, Diamonds3, Hamilton22