You know since the Dixie Chicks are the top selling female band of all time, maybe it's not such a bad idea for Tim McGraw to follow in their footsteps!
Funny,they dont even show up on any of the top ten lists that I've found.
countrymusic.about.com/od/toppicks/tp/CntryBestSeller.htm
According to these guys they have two of the top ten selling albums in country music history.