I think your best bet for freerolls, is
888, Natural8, and GG Poker.
All 3 have regular, and frequent freerolls. Natural8, and GG are pretty much the same site
Another good one, especially through CardsChat, is Americas Cardroom, or Black Chip Poker (again a clone site.)
My personal preference is 888. I have an easier time there getting into the money.