I'm interested in an iphone 4s. What is the best plan to go with?

Also are there any hidden fees I should be aware of?

I own an iPhone 4s and have been using it with the AT&T Family plan for the past year (my monthly bill is $50 a month per phone, unlimited data). I formally used T-Mobile and have found their service to be slightly lower in quality than AT&T, albeit at a lower price. Keep in mind that the iPhone that you pick may or may not be offered by the service providers that you are considering. I'm getting ready to switch carriers myself, so I have been researching the marketplace and I have found that the best overall service provider is Verizon (customer service, connectivity, and speed). They also happen to have the highest overall prices for their respective plans. Looking back through the years, there does seem to be a strong connection to quality and satisfaction of service to the money that I spent. Once you settle on a service provider just make sure they offer a flexible contract so that you have the option of going up or going down the many different service plans and price points that they offer (without a penalty). That way, you can pick a low end plan (less time, less data, less money) and try it out for a month or so knowing you can always upgrade to a pricer or even an "unlimited data plan" if you keep running out of minutes and gb's. Always ask plenty of "what if" questions to your customer service person before signing on the dotted line. Read all of the small print on the contract. A two year contract can feel like an eternity when you are dissatisfied with your cell service or phone-type. Of course, you can always consider buying an unlocked or non-contract phone and pre-paid phone service. Personally, I would stay away from that idea unless you feel you have no choice due to an unstable monthly cash flow (or credit issue).By signing a contract with a cellular service provider, you are getting a substantial discount on your hardware (typically in the hundreds of dollars). Also, you gain power and clout as a customer of that company the longer you stay with them. Customer loyalty is the service providers greatest asset and they will bend over backwards to keep you as a current paying customers. Translation… More money, more power, more respect, and ultimately more savings to you.