The speed of a server at any moment depends on the load at that moment. So it's unlikly that any IP is always the fastest.
But why not try a few yourself?
Kees
Hi,
I need to know the some free proxy softwares which provides Fastest USA IPs.
Thanks in advance!!

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic