You people get into absolute histrionics over this issue. Fact is, AT&T coverage is very good in some areas, and absolute garbage in others. This is true for Verizon also, but Verizon does offer a much larger area of 3G, albeit at slower speeds than AT&T in many cases.
For me, I used an iPhone since the day it was released in 2007. I had EDGE coverage, and while slow, it was reliable. As the years progressed, I upgraded to a 3G and then an iP4... my service deteriorated steadily as more and more users to the network were added. Eventually, in our area AT&T ceased functioning entirely, first for data, and then eventually for voice. Calls would go straight to voicemail, texts would take hours to receive, etc. After a massive local uprising (I'm not kidding, literally thousands of calls to the office of the president, and a personal apology from the AT&T regional president to our community), we mysteriously got upgraded to 3G, well ahead of many much larger communities in our area. In the meantime, Verizon steadily improved its coverage (3G) to the point that the ONLY reason people stuck with AT&T is the iPhone.
I dropped AT&T 5 months ago, and waited patiently for the Verizon iP4. Received mine Monday, and have been extremely happy.
Your comments that "everyone is just a bunch of whiners" is complete BS. It is a region by region issue.