As much as we'd like to say there are, there are no cheat-free servers in MoH:AA. Everytime we stop them, they come up with something else.
However, if you want a server that is aggressively anti-cheat, monitored relentlessly, and remains on the edge of anti-cheat software, you should try the PureServers.com Public Server, or AllAboutNothing.net's server.
PureServer.com's IP is: 204.157.6.21
They run Allied Assault
For AllAboutNothing.net's server IP and the files you'll need to play there, visit
http://www.allaboutnothing.net
They run Spearhead
Hope this helps