I've played City of Heroes, Champions Online, DC Universe, Mass Effect and Skyrim : and to be honest, a lot of them have systems, features and power mechanics that singularly are impressive, but don't quite work as well as I wish they did, but together and with some improvements - they could work great.
City of Heroes and Mass Effect 3 both have force field powers allowing you to create domed force fields that unfortunately don't block weapon fire, or physically block/repel monsters/enemies effectively.
Would it be too much to ask for a force field power set that did manage to block projectiles.
Most of the force field powers just passively add defence increase to the inhabitants of the force field.
City of Heroes also had a unique PhysX utilization in many of is powersets that I loved.
Eg: Gravity Control - The effect it had when lifting debris from the ground and launching it.
Eg: Storm Control - the blizzard effect / snow storm effects: when you could anchor the effect to a player, and then it would blow trees, suck leaves, and everything.
As far as Skyrim goes - I'd love to see image space modifiers in use.
Eg: Imagine powers that altered your screen space - providing tinting or even colorization of enemies
Heat Targeting, Seeing Enemies through walls etc.
Image Space modifiers could also be used to facilitate invisibility, and the ability to pierce that invisibility.