Net10 and it's sister StraightTalk are both owned by TracPhone. The coverage you get depends on which phone model you buy. Each phone works on a different real network (Verizon, Sprint, AT&T, or T-Mobile).
VirginMobile (like its sister BoostMobile) is owned by Sprint. Those 2 operate on Sprint's prepaid network.
Look at the prepaid maps for the 4 major carriers and that will tell you which network coverage you want. Then, pick a phone from Net10/StraightTalk that uses that network.
Personally, I like Verizon's coverage, so I have a Samsung Galaxy Proclaim (available on both Net10 and Straight Talk).