I have an older Midland. It still works fine. Make sure to get one that is "SAME" (specific area message encoding) compatible. This allows you to only program alerts for specific counties. I don't feel like I get a lot of nuisance alerts. My main reason for having one is to have something that will wake me up at night if things get bad. The National Weather Service has a good page on receivers.
http://www.nws.noaa.gov/nwr/nwrrcvr.htm
http://www.nws.noaa.gov/nwr/nwrrcvr.htm