The Wireless Report has done a survey of the plethora of plans, services and tiers in an attempt to define a baseline wireless customer to compare the top four U.S. wireless carriers in the U.S.
The report sets the baseline user as a person who uses 400 to 600 minutes, voicemail, call waiting, caller ID, free nights and weekends, nationwide toll-free calling and national roaming, 200 - 500 text messages, and basic internet access from the handset.
Using this baseline user, the big four shake out like this:
The report is rather detailed, but a recommended read, as it outlines the significant differences in services between providers (the article also includes detailed coverage maps).