Which Carrier Has the Best Data Plan

Data Plan Pricings for Major Wireless Carriers:

AT&T: low usage $15/Mo for 200MB; high usage $25/Mo 2GB
Sprint: low usage $15/Mo unlimited; high usage: Only bundled with minutes
T-Mobile: low usage $24.99/Mo for 200MB; high usage: $39.99/Mo Unlimited
Verizon Wireless: low usage $15/Mo for 150MB; high usage: $29.99/Mo Unlimited