Best fun fast-paced lanparty action games...

I'm hosting a lanparty next week and I'm looking for a list of some fun fast-paced ACTION games that are relatively simple. I'm not looking for large complex commerical games like CoD, etc but small "simple" games that have a very small learning curve but provide hours of intense fun.

The only one I know of is "Babo Violent 2" but does anybody else have any suggestions?

-Pete

doom 1 or 2, serious sam - are lan classics

DIALBO 1 **doesnt work on lan with vista** (easy learning curve but not as fast but SOOOOO fun on lan)

Serious Sam: The First and Second Encounters fit the bill perfectly. Serious Sam 2, not so much.JP_Russell