My favorite combo would be Thorn Elemental and Armidillo Cloak. Here's why:
Thorn Elemental is a 7/7 unblockable ON ITS OWN+ Armidillo Cloak which gives it +2/+2, trample, and get as much life as damage. If I really want to devestate my opponent I wait until I get all my Forest Mana(which is pretty darn long) then summon 1 or 2 Thorn Elementals and Armidillo Cloak and Blanchwood armor which makes it a 45/45, wait for next turn since I can't attack with a newly summoned creature then next turn, if I have these in my hand, I add Giant Growth, Explosive Growth with kicker cost, and Invigorate it becomes a 57/57. How's that of your death?
If you want more info on my white/forest deck e-mail me at gotensfr@hotmail.com.
-Sergio R.