I really dig co-op games...there's nothing like taking on hordes of cheap-ass enemies with a buddy. Sadly, there are very few Co-op games out there...why more developers don't add in this great feature is beyond me. At any rate, below is a very nifty list of Co-op games by "mr bernard langham", that I found on usenet. I'll try to keep it updated as he updates it...
At the bottom, you can see the few updates I've, personally, added to the list based on games I've found that offer co-op gameplay. If you know of any games that offer Co-op gameplay that aren't on the original list, or in the list with my addtions, please email me.
PC Coop Game List
Based on a list by Michael <c...@iinet.net.au>
The essence of cooperative multiplayer gaming is that of "working together with friends to solve the single player game." Accordingly, the term "coop games" as used herein means games which support simultaneous cooperative network play over the course of the main single-player campaign, or at least individual scenarios thereof.
It does *not* include the more common FPS team vs team deathmatch or capture-the-flag styles of multiplay, where one team may be composed entirely of bots and the other of cooperative players (e.g. Unreal Tournament, Battlefield 1942, Joint Operations etc).
To be included, strategy games must support full alliance options, where two or more human players with separate empires can pool resources, share cities, engage in trade etc, and cooperate against an AI-run empire or more than one.
* = recommended/popular
First Person Shooters
This section is an unofficial addition to the list above. It contains PC games that I have run across that offer Co-op gameplay. If you know of any games that offer Co-op gameplay that aren't on the original list, or in the list with my addtions, please email me.
Aliens vs Predator 2
Doom 3: Resurrection of Evil
FEAR (with CoOp Warfare patch, only selected maps)
Judge Dredd: Dredd vs. Death
Medal of Honor: Allied Assault
Serious Sam II
Unreal Tournament 1999/GOTY: Monster Hunt
Unreal Tournament 2004 (Alien Swarm Mod)
Arcanum: Of Steamworks and Magick Obscura
Codename: Panzers, Phase 1
Commandos 2: Men of Courage
Full Spectrum Warrior
Ground Control 2: Operation Exodus
Icewind Dale II
Joint Operations: Typhoon Rising
Titan Quest, Immortal Throne
Twisted Metal 2
Typing of the Dead(LAN only)
The following links provide further info on how to certain games to allow for co-op(location of patches, mods, etc) as well as various thoughts on the co-op play itself.