Depending on the type of game you design, you may find that you need a voice actor. Once you have your script and roles set up comes the hard part. Who will you choose to be your voice actor? Now you could do it yourself, but you’re probably much better off hiring one. Here are a few places that you can get a voice actor.
He offers numerous types of voice acting. His prices are reasonable and he has a professional voice. Check out his site here.
Phil, over at Operation 42, does voice overs and music for flash games. The site lists his prices and also includes some free audio.