And I would have gotten away with it if it hadn't been for those meddling kids!

Anyone looking for ideas to spice up their dungeons could do worse than watching an episode or two of Scooby Doo. There has been a LOT of horrible, HORRIBLE Scooby Doo stuff produced over the years, but some of the modern stuff is very good. I highly recommend Mystery Inc series and one of the newer movies, Legend of the Phantasaur has a butt-load of good ideas, from ghost dinosaurs to a honest to Zod dungeon crawl at the end as the Gang escapes from a mine.
The movie is fun, but not nearly as good as the credits
Just from this I have ideas for a haunted trophy room, a hypno-trap, carnivourous boots (this was actually from a commercial) and the titular Phantasaur which is a cross between Godzilla and a T-Rex (stats forthcoming after the wife goes to work).