I want to get an iPhone but I don't know which Service Provider to use?

I want to get myself an iPhone but I know they don't work unless you have either Sprint, AT&T, or Verizon service, not Cricket. I used to be a customer of all of those service providers however I don't know how their current rates are going. Doesn't anyone know which one is the most cost efficient as well as has the best reception AND reputation? I'm normally a Cricket customer because they are totally Recession-victim friendly so I'm left feeling scared switching to a company that is just going to blow smoke up my but just to get me to sign on the dotted line and thus signing my credit over to them. I need help with figuring out this mess and any advise is helpful. Thank you very much.

Jessica

Added (1). I failed to mention that I'd prefer to pay something like a month by month plan without having to cower in fear from the monstrous 2 year "solitary confinement" contracts. I prefer not being worried that my credit is going to get screwed if I, say *knocks on wood*, lost my job. I don't have any other financial assets so my job is the only way I would pay for a service plan. If there isn't a plan like this then I'll just suck it up and offer over my credit to the money greedy corporations.

Why don't you try vodafone they have very good rates and are very reliable too.

Unlock it and get straight talk or virgin