As I understand it, the answer is the same for a C Corp as it is for an LLC: it depends on the nature of your business. If you do a lot of business in your home state, I believe most business attorneys advise incorporating in your home state. If not, like a typical dot com company, than it is fine to incorporate in another state.

For many small businesses that usually opt for LLC structures, I've heard anecdotally that Nevada and Florida are good states with LLC-friendly laws - as opposed to Delaware and its C-Corp-friendly laws.

Disclaimer: I am not a lawyer, so take this with a grain of salt. I would recommend consulting a lawyer to get a more definitive answer.