Any recommendations for reliable burglar alarm systems? So many options!

I'm overwhelmed by the sheer number of burglar alarm systems out there! From SimpliSafe to ADT to DIY setups, it's hard to know where to begin. Are there any particular brands or systems that people have had really good experiences with? What features are essential, and what's just marketing hype? I'm looking for something reliable and effective, but not looking to break the bank.