I got a new cell phone on Cyber Monday so now I've got an extra one. It's got quirks but is totally usable and completely free.
So the phone is a Samsung Galaxy S III. I got it from my old roommate when my previous phone died one day. It was originally on the Verizon network but the phone is now unlocked and available to use with any Pre-Paid phone/data service. I know it's compatible with CDMA carriers (Verizon, Sprint, PagePlus, MetroPCS, etc) but I'm not sure about GSM.
All it needs to work as a cellular device is a valid SIM card associated with a phone/data plan.
The phone is perfect with phone calls and text messages. I'm not sure about the cellular connection, I had been getting slower speeds which is what caused me to get a new phone, but that problem has persisted and I don't think it was the S III causing the issues. 4g LTE connection did work reliably, just slowly. The Wifi is really finicky on this phone, you basically have to be within 5 feet of a wireless router to get it to work and so I just left it turned off most of the time.
There is a hairline crack in the screen. You can see it in the second image. There is also a bit of damage near the top-right corner with the glass. Neither of these can really be felt when using the phone. They were there before I got the device, so have not gotten any worse after 6+ months of usage.
The case is a bit bulky, but very secure and comes with the phone. I'm sure you could get a smaller case for it if you needed to.