Hmmm... Are you talking about amiga-specific games or Cross-platform games? Amiga-specific ones include DynaMite, and iirc Foundation, Napalm, Earth2140 and Freespace all include TCP/IP gameplay, so while there won't be servers to look up, you could connect directly to another amiga playing them... Cross-platform ones include Quake, Quake II, Heretic II (I think), possibly Earth2140 and Freespace, FreeCiv, and probably others I can't remember at the mo...
