It is definitely not for everyone, but I love my Nextel. Around here the service is very good, and I use the Direct Connect more than I ever would have thought, especially at work. Some plans come with unlimited DC minutes, otherwise unlimited can be purchased for an additional $10/mo. The biggest problem with the Nextels is that they are a bit expensive.
I pay $60/mo for nationwide service with unlimited Direct Connect. I have 400 minutes but free unlimited incoming calls. I never come close to using my full 400. Actually I rarely break 200/mo.
I have heard very good things about Verizon. I probably would have gone with them, except they do not have home service in Kalamazoo so they were really unable to be an option unfortunately. My pager is through Verizon, and that has great service though
I can second the thoughts on avoiding Sprint. Back when I lived in Detroit, we had some very bad experiences with their wireless service.