<< I was speaking with an ADT rep recently. He was explaining that burglers are now getting more brazin and getting into homes with security systems. They will run through a bunch of garage door opener codes until they hit the one that opens your garage door. Then, if you have attic access in the garage, they will climb up and make their way to the master bedroom and then break through the ceiling. Grab some valuables and leave back through the attic never tripping any window or door sensors. >>
ADT provides motion sensors too. I only have one, in my living room where most of my stealable stuff is, but many people have multiple. Motion sensors can be tripped by dogs, etc, but they're built not to. And you can set up the system so that the door and window sensors only are active, with the motion sensors off. This is in case you want the security system on when you're home.
Oh yeah, get a system with wireless fobs. Turn it on and off remotely without having to worry about stoopid codes all the time.
Also, are your phone lines exposed? If so, something like Chubb or ADT is useless stock. They just cut the phone lines - problem solved. In that case you might be advised going for a system with a cellular backup.