Lost Horizon (1973)
Vastly inferior remake of the 1937 classic, and widely considered to be one of the worst movie musicals ever made. Shangri-la is portrayed less like a utopia and more like a New Age cult with a dash of Mighty Whitey, the actors are obviously phoning in their roles even during the riot in the opening scene, and the musical numbers are dreadfully dull.
For a more in-depth look at the film's awfulness, here's the Musical Hell review:
Another musical from the 70s though not as mind-numbing as The Apple (it comes pretty **** close though). It's an absolute goofball of a movie starring the one and only Michael York as some Super Ambassador to the world who is apparently the only one on the planet that can solve ALL TEH PROBLEMZ! His prowess is so legendary in fact that his plane gets hijacked and crash lands on the top of Mount Everest... or something. There he and the passengers discover the what can only be described as when Buddhism meets Disneyworld. This movie is such a gooey gem, you guys have to do it. C'MON. C'MOOOOOOON!