I would buy iPhone 4S because iPhone 5 is new. If something should go wrong with them being that they are new then :/. If u get the iPhone 4S, it has been around longer and if anything were to have gone wrong with it, it already would have happened.
Yea i have the 4S ind I'm very happy with it only difference is the 5 is about 6 seconds faster and a screen thats a little bit bigger and a apple A5 chip there is a lot more extra updates to with the new iOS 6 update and the 4S has all the same updates as the 5 like the 3D map view. Im jailbroken so that makes my 4S do more than any iPhone all together lol ;) plus one bad thing about the 5 is the new plug it uses witch means you will not be able to use some of the docks and iPod radios and the size difference make it so you cant use iPhone 4 cases with it you need to get special ones just built for the 5