What type of cooking surface? Gas, electric coil, glass top electric, other?
My non-enamel coated cast iron skillets have warped just enough that they won't sit flat on my glass top cook surface. It's a major downside of glasstop, that's not an issue for gas. For some reason my enamel coated dutch ovens from Lodge and Le Creuset have held up fine, though the Lodge's enamel coating didn't. Make sure you wait for Le Creuset sales at their outlets, if you go that direction.
We also have been happy with the Emeril 12 pc set.
I'm strongly considering The Ringer for easier cast iron cleanup.