I love Verizon. I have been with them for about 8 years currently, probably 10 or 12 total (tried Nextel aka Sprint and switched back).
I guess it depends on where you live, but I find they have really good coverage for me (in RI/nearby MA), everywhere. I also have alot of family (almost all) that are on Verizon, so it makes wireless calls cheap! (Free calls to other Verizon customers.)
If you're looking for super hightech phones though, a la IPhone, you'll have to check out AT&T.
ETA - Verizon does have really great phones, too, but not the IPhone. The Droid is supposed to be pretty comparable though, and that's available on Verizon.