I've been pretty frustrated with Verizon customer service over the last three months, and have found out that the early termination fee is prorated based on how many months you've been in your contract, so I'm seriously considering leaving for another carrier. That said, I've been looking at Sprint and AT&T as my replacement. I crossed T-Mobile off the list when I visited a store and all the phones were fake display models. I heard some bad things about their new 3G service, and the fact that you aren't allowed to try out the phones makes it seem like they're hiding something.
I hear tons of bad things about AT&T, but all my cousins have that service and don't have a problem, and when I had it for two years, I didn't notice anything bad. I hear really bad things about the iPhone, but it wasn't even on my list of phones because I want a keyboard. My brother highly recommends Sprint and his smartphone doesn't have problems when he's visiting me in Manhattan or Brooklyn. I'd hate to stay with Verizon because they have a monopoly on NYC - it makes them seem more evil to me in a "Ha ha, you have no choice" way.
Lo and behold, I discovered this site that shows users' cell phone signal strength and dead spots. It pretty much shows that no service is flawless in NYC. I'm thinking of a Blackberry Curve 8900 or the new Palm Pre from Sprint at this point, unless AT&T gets a new iPhone that has decent coverage, a realy QWERTY, and MMS capability.