I would seriously LOVE to be able to just sit in a bloody chair without a load of faffing around with emotes.
I would love a zip line style travel power
I would love tentacles as a power set, either ones that extend from the fingers (blocky hands in our case) or the back or torso. They would fit melee and control power sets well I think
Alternative pet models would be great, for existing pet powers, especially some of the controller sets.
I'd quite like a "Musician" MM power set. Different musicians, with various instruments, setting their grooves on enemy mobs and destroying them with the coolest of sounds! Can you dig it?