I would suggest Craigslist because it is an online classified ad site. I have sold two cars to local buyers and had no problems.
I screened the people who replied to my ads, and discussed the sale on the phone with serious buyers before inviting them to look at the cars. I actually closed the deals at a local coffee shop and did cash only transactions. It is important to have a witness to sign off on a transfer of title between the buyer and seller.
Oh, make sure you call your insurance agent and cancel your policy as soon as the deal closes- the new buyer will have difficulty insuring the car if you're still listed as the owner.