21. After Earth (2013)
This futuristic whatzit stars Smith as the fearless, emotionless General Cypher Raige (his actual name!), stuck on a humanity-free Earth, guiding his son (played by his real son Jaden, who really needs some acting lessons) in making sure they get off this godforsaken place. The actor has himself to blame for this one; while directed by M. Night Shyamalan, Smith is credited for the story.
20. Shark Tale (2004)
In Dreamworks' animated comedy, Smith is all up in the water, voicing a slick-ass fish who starts a hustle with a vegetarian white shark (voiced by Jack Black) so he can become the biggest, baddest fish of the sea. This cartoon malarkey boasts an all-star cast (Angelina Jolie, Robert De Niro, even Martin Scorsese!), but unless you’re a kid, you might as well leave this one sleeping with the fishes.