You should check out:
http://www.radarbusters.com/ ...This site has, probably, the most comprehensive and detailed reviews on the net. I, personally would go with the Escort Passport 9500ix; if you're on a budget, go with the 8500 x50; same radar, just not as many 'other' features. But you can't go wrong with Beltronics and the Valentine system. Just do you're homework first. If you buy something crappy, it will cost you with unnecessary speeding tickets.