I agree with Rdizzle, Get a Pioneer. I have tried other brands but now I only buy Pioneer. Best bang for the buck. Their $100 stereos sound better than other brands costing 3x as much.
If you live near a Circuit City the offer free installation with and car stereo purchase over $99.
Here's one for $89, web only special but they always match their web prices. Since it is originally more than $99 it may qualify for free installation. (warning, you probably will get hit with the$30 installation kit but if you had an aftermarket stereo in the car already you may not need it.)
http://www.circuitcity.com/ssm/Pione...oductDetail.do