What service & plan would be best for a iPhone?

I'm looking to get a iPhone and I'm wondering what service/plan would be the best if I'm leaning towards the iPhone?
Also when does the iPhone 6 come out? If soon. Should I just wait for the iPhone 6?

For an iPhone definitely Verizon! I don't have Verizon, but I know it's best! No exact date for the iPhone 6 it's suppose to be out this fall though.