Code Alarm hands down. NOBODY uses real panic sound, only Code Alarm does. How often do you hear the typical monotone horn honk or siren and not even bother looking? What real panic sound does is honk the horn at random. Code Alarm is the only brand I use because it's the only brand that does what an alarm is supposed to do; grab your attention. I've installed both Code and DEI(viper, clifford, python, avital.....) Code is the company I saw the least returns and that I installed the longest. I saw more DEI stuff come back because it messed up within 6 months than I saw with code for 3 years. I've had the same system for 4 years in my Burb now that I've pulled out of three different vehicles. The wife's Yukon has a system that works like the day it was new, it's over 6 years old and has been swapped between two different vehicles. The only remotes I've had to replace between either system is the one that went swimming with me.