Phantom Tracker is pricey as hell, but comes with 24 hour monitoring services so you get a phone call from an actual person if your alarm is activated. That way you have a chance to check it out yourself before sending the cops out to every false alarm. If you fail to answer the call, they only send the cops if the bike is moving (so don't ride off without disabling it).

Not sure how hard it is to defeat, but the response time is so quick by the monitoring service, I doubt anyone but the best of the best bike thieves could pull it off.

Other than that, just get a siren alarm that is enough to convince would be theives to move on to an easier target, park it in a garage, and get insurance. If you have to park it outside, keep it covered all the time when it is parked so random people coming and going don't see it sitting out all the time. Worked for me before I got a garage. Unfortunately, I didn't start doing that stuff until I had one stolen!