I'm looking to get a new cell phone/plan in San Francisco, and wondering which company has the best coverage and service. I'm especially interested in AT&T, Verizon, and T-Mobile. Any advice?

I dont live in the San Francisco area, But I wouldn't go to At&t. Everyone that I ever talk to about them says the get ripped off by them. I have had verizon for the last three years and have been very happy with them.