I’m a big fan of the systems that link to your cell phone and give you video of anything going on at the house particularly if an alarm is triggered.
Beware that in many localities around the country now you can get either no service at all from police for an alarm, very delayed service, and in quite a few if they respond to a false alarm you can get handed a ticket/bill. That being the case look at the various options available and see who has the lowest false alarm rates, highest recommendations in your area, and consider whether or not you want the alarm company to notify you, police, or both should there be an alarm.
There are two schools of thought about putting a "This Home Protected by XYZ security company.
One, pro’s will probably know what system you have and the easiest way to disable it and that you have something of value in the home you’re willing to spend money to protect.
Two, it is a great deterrent to most as they are looking for soft targets, not a fight.
When looking at a move, be sure and look at crime rates for the neighborhoods you are interested in.