Get a whole hoard of dogs to protect you.
someone who breaks in cant shoot/attack back ALL of them. Although I'm the type of person to jump in front of a bullet for my pets, defeating the purpose....lol.
anyway, I hear that Airedale terriers can be good guard dogs if trained correctly. But for a more common guard dog, German Shepard or dobermans are good (as a lot of people have already stated.) if you're allergic to dog fur or anything though, Airedales are a good choice since they have hair and don't generally shed :3 (bad is that you have to groom them)