Car alarm help?

i just got my car raided last night. about 1200$ of stuff was stolen. But it was more than just my car. The cops found the people and have already got them into custody. Most of my stuff they have, but I want to prevent this from happening again. I have a 2001 Plymouth Neon and I do not have automatic locks or windows. I was wondering what the best car alarm for me would be. thanks in advance