For the past three years T-Mobile has been my cellular carrier. I chose them back at a time that I was traveling to Europe periodically and wanted a service that would provide access via the European GSM carriers.
Prior to T-Mobile I had been with Verizon Wireless.The more time goes on the more I like T-Mobile. Their customer service has been pretty good, at least when I needed something it was possible to get it done. I’ve had my phone replaced at least twice. I’ve also had a failed SIM card replaced.