Tremors was amazing, one of the best B movies ever made. Fred Ward and Kevin Bacon are what made it so good though, so I haven't liked any of the sequels all that much.
In general, Fred Ward is in quite a few of my favorite bad movies:
Tremors, Naked Gun 33 1/3, Remo Williams: The Adventure Begins, and Timerider: The Adventure of Lyle Swann. He was also in a few good ones like The Right Stuff and Uncommon Valor.
Other great/bad movies that I like:
Big Trouble in Little China
Robocop 1 and 2
Motorama
Six String Samurai
Heroic Trio series