114. The tripwire room, 40 x 40 ft, filled with garbage, empty boxes, bones, rats, stirges, etc., and also filled with tripwires in every square, hundreds of them like spaghetti in all directions...then make an empty corridor where the real trap is...
115. Fun with teleporters - make an otherwise nondescript hallway a teleporter, put some mist in the whole area, and have the characters continually teleport to two rooms back, see how many times you can get them to walk the same hallway before they figure it out...
116. Fun with time travel - have the party hear movement just ahead (it is themselves about 30 seconds into the future), and let them chase themselves...maybe they will fireball or do some long ranged stuff to themselves! Fun fun fun...
117. Fun with moss - make the entire dungeon tilt down at a 30 degree angle and have the floors all covered with moss, balance check to stand, or fall and slide into walls, etc...
118. Fun with water - Make the entire dungeon filled with water, and make it filthy nasty Star Wars Episode IV trash compactor-type nasty, and let the party hear things splashing, or catch a glimpse of an eye, but nothing ever actually happens - until they get to the way into the bad guy's lair, and its a huge plug in the floor, which of course will flood the bad guy's lair if it is pulled, and if they do it also causes huge quantities of water to rush in and send them tumbling down into the horrors below unprepared...