i bought the cheapest phone they carry to try out their service, which is more than adequate but after 8 months the phone i spent $15 on is kaput.

i want to keep the same service and phone number but don't know which phone to "upgrade" to.
what do you people recommend? i carry a blackberry without service to keep a calendar and the other features so all i really need the phone to do is make calls and send the occasional text message.
are all of their phones of the same quality? would my "upgrade" be just purchasing a polished turd?
what say you people?