I haven't seen it in quote a while, but I really enjoyed Time Bandits.

For a more recent underappreciated film, The Huntsman: Winter's War is actually a pretty decent, fun fantasy adventure. Chris Hemsworth is really fun with a performance similar to Val Kilmer's Mad Martigan character from Willow, and Charlize Theron completely chews up the scenerey in the few scenes she's in. (I haven't actually seen Snow White and the Huntsman, so have no idea if it's similar)