This thread turned out even better than I expected it to.
Next combo:
Invisibility or Teleportation.
Both can be extended, no blindness, ending up is solid objects and no telefragging (because this teleportation comes with an inability to appear inside a solid).
I have an easy opinion on this one; teleportation hands down. No need to catch the bus, enhanced laziness (teleport to fridge, etc), impress any female (also possible with flight), never need plane tickets, easy vigilante action, etc. The list goes on and on.
It's why I had Teleportation as one of my four desired powers from this list (along with Mythpower: Mnemosyne's Memory, Reincarnation Determination and Omnipotent Power Mimicry). I'd give invisibility to one of my friends without thought.