10. Indiana Jones and the Kingdom of the Crystal Skull (2008)
Steven Spielberg's blockbuster '80s franchise featured a young, active Harrison Ford and campy, fun adventure stories. Two decades later, the follow-up is an aged Ford in a rehashed plot.
9. Blair Witch 2: Book of Shadows (2000)
The Blair Witch Project was an intriguing premise for a movie. The sequel about kids returning to the woods and then dying is a retread of the original film, but without the gritty handheld cinematography or buzz-worthy viral campaign.
8. Caddyshack 2 (1988)
The first Caddyshack had a gopher, a crazy Vietnam vet groundskeeper (Bill Murray), and a Baby Ruth floating in a pool. Why mess with perfection?
7. Jurassic ParkIII (2001)
Spielberg's franchises recur on this list because he oftentimes makes an excellent original film, only for his premises to quickly turn sour in new hands. So it is with Joe Johnston's sequel of Jurassic Park, which incidentally is the only one not based on a Crichton novel.
6. Batman Forever (1995) and Batman & Robin (1997)
After Returns (1992) but before Begins (2005) was the dark period for the Batman franchise, known as the late '90s (AKA: the Joel Schumacher era).