Agreed. Napoleon Dynamite is a perfect choice for a "best-worst" movie. I feel exactly the same way; had no idea either why it was popular when it was released. But afterward, while thinking & talking about it, I realized that I quite liked it. And I caught the last half of it on HBO recently, and found it hilarious to re-watch. Classic best/worst.
The Life Aquatic with Steve Zissou is another oddball I'd nominate. People either seem to love it or hate it. Both my wife and I were sort of negative about it at first, but by the end, I thought it was great and quite enjoyed it. My wife still thinks it had very few redeeming qualities. Actually, most of Wes Anderson's movies are like that; The Royal Tenenbaums, Rushmore, The Darjeeling Limited, etc. A weird, quirky, love/hate, best/worst sort of vibe.
And if we're creating a special class for Tom Cruise movies, my nomination would be Magnolia. Perhaps I just don't get it, but even after watching it and reading reviews, I still don't understand what or why any of it happened, nor why I wasted my time watching it. I think that flipping through 2+ hours of infomercials would have been more interesting and more worthwhile. But that's not a "best/worst" for me, just simply a "worst".
