Made the switch from Verizon to U.S. Cellular about 18 months ago, and very pleased.
New iPhone for free, military discount, unlimited everything, unneeded data rebate every month, great service and friendly people.
Have heard their referral rebate is now up to $100 to both the referring party and the party changing service to U.S. Cellular. Wait, if you can, until one of their free phone promos comes up and make the switch then.
Good luck.
There is no such thing as a "free phone", unless you're talking about an Obamaphone.