Basically anything from DEI (Directed Electroinics). The own about every "good" alarm brand out there. Viper, Cliford, Avatal, Phython, Sidewinder, Hornet, & ect...I was an installer for audio shops for about 8 years, and have seen it all, they are the best. Stay away from anything you haven't heard of. And anything sold and installed in a Circuit City, Best Buy, or any other big retail store. Find a local car audio shop and see what the sell. Or better yet check out the dealer locator at:

http://www.directed.com