The best idea is not to have one at all. Burglars actually seek out houses that have CCTV and burglar alarms to rob. They know that a house with an alarm is going to have something worth stealing . I worked inside a UK prison and several robbers told me that they look for houses with CCTV and alarms as they know it will be worth robbing them. They wait until no one is home, preferably on holiday. A 'professional' burglar will be in and out again in less than 2 minutes, no time for any response from the police or the alarm company.