They must be centrally located in the USA.

Any suggestions?

Are you talking about for a game server or for a whole box?

http://defconservers.com

They have central locations in Dallas or Detroit. Defcon is ran by adults as a full time business...not some kid trying to make a quick buck ;)

www.gamedaemons.net

If not a whole box, the game type would be useful info.

If you're looking for a whole box, centrally located, I would recommend theplanet.com. They have a great network...

For Chicago-based, you could go with ServerCentral.net (I don't use them, but the pings/network is also very good)