After an expensive afternoon in the Apple Store I am now retiring my 4S, so thought I'd offer it up on here first.
It's a 4S (SIRI) and has the latest software on it.
I don't think I ever bothered getting it unlocked, so it works on EE, T Mob & Orange.
It's had a case and a screen protector on it since the day I bought it, and I've just noticed that the film on the back has never been removed, so I would describe the condition as Very Good to Excellent, but it is used.
I still have the original box (IMEI number on the bottom matches the phone), and the original headphones (unused) and the USB Mains plug (also unused) are still in it. The charging cable is included but is used (if you wanted to give this as a present I'll see if I have a new one anywhere).
I'll include a couple of screen protectors for it if you want them.
Phone is black and will be reset tonight once I've made sure everything is transferred over.