[Booyakasha]

Steampunk would be pretty cool for a dungeon. Maybe something akin to Gnomeregan in WoW, featuring loads of clockwork enemies and strange machinery.

Actually, speaking of Gnomeregan, it might be interesting for them to have one dungeon where, instead of monsters, there are competing factions at work, so your dungeon crawl takes place against the backdrop of a power struggle. Say, there's the dungeon's ancestral guardians trying to keep out intruders, and there's a band of pirates trying to plunder the dungeon's valuables, and maybe a third group with its own agenda. You can either use the confusion to help you slip through unnoticed, or aid one group in forcing the others out (thereby earning their gratitude, and a massive reward). Granted, it'd be tricky to implement. It'd also be a big shift away from the standard LoZ dungeon formula, Ehhh.