Does anyone have a recommendation for a security system to monitor their home?

[nglodnig]

Dig up some mines from nearby conflict zones and plant then round your house. The explosion when stepped on should be a good alarm. Try not to step on them when watering the plants and warn the gardener (tongue in cheek reply not serious honest)

[The Fugitive]

Already been mentioned that cameras won't prevent burglars getting in. Increasing visibility is more important. Railings instead of solid garden walls and bright exterior lighting would help. Lockable gates over doors and grills over windows are good visual deterrents. Maybe a few timers to switch lights on and off when you're away?