I use ADT, the contract isn't very long, didn't cost much to install and activate. Monitors smoke, carbonmonoxide, doors, windows, and motion. Uses cellphone technology with a battery back up. Has a built in speaker and mic. Only costs about $50/month for monitoring. But to be honest, I haven't ever used any other brand so I can't honestly tell you if it is any better than another brand. Oh, and the equipment is from Honeywell and GE.
