I have been with AT&T for around 9 years. I was irked when they turned into Cingular and double irked when they switched back. Beyond that I have no complaints whatsoever.
9-12 years. The wife and I both had cells with Cingular when we were dating. Have been with them ever since. Never had any major issues with their service, so no reason to switch.
I have been with AT&T for close to 15 years I got my first phone back in the summer of 1995 . The company in upstate NY was known as Cellular one , I got a free Ericsson phone when I donated $15 to the Special Olympics . The thing was a brick .