I'd love to see more branching dungeons. Right now it's basically a big corridor. Some of the older dungeons had side rooms which housed a chest or so, and I think there's literally only one which gave you a choice of route (Tam Tara Deepcroft story mode), and even then it amounted to a parallel corridor.

So, I'll chime in with my support for alternate dungeon paths. Doubly so if each route had its own different bosses. At the very least it would make repeated runs of the same dungeon more interesting and less cookie-cutter.