What form of payment should I accept while selling my car on Craigslist?

I am selling my car on craigslist.

A guy offered me my desired amount and he has agreed to pay the full amount in cash.

Is cash the best form to accept the payment? What about fake bills? How would one counter that?

Are there any other scams I need to be aware of while selling my car on Craigslist?

Thanks.