hoarfrost or hibernate
I think it depends on the sophistication of the build. On characters I'm leveling up, or haven't bothered with IOs yet, I like hiber. It recharges pretty quickly and I even use it just for endurance refills. With uber sets with no Endurance concerns, yeah, Hoarfrost.
Global = Hedgefund (or some derivation thereof)
If you had to choose between hoarfrost and hibernate and there are no extra slots to spare, which would you choose?