Might as well make a list of shit I own or is free to download.
Sorted by minimum requirements
StarCraft futuristic RTSus.blizzard.com/en-us/games/sc/Distribution: Pirate copy
Performance: Oh come on anything can run this
I absorb massive cock at StarCraft and RTS games in general but it's a LAN staple.
Available modes: RTS, custom maps
Counter-Strike round-based tactical FPSstore.steampowered.com/app/10/Distribution: $9.99 on Steam, free mod for Half-Life owners
Performance: If you can't run this then Jesus Christ
Still probably the number one online game in the world. Counter-Strike defined LAN and online gaming.
Available modes: Hostage rescue, bomb defusal, custom map game modes
Day of Defeat World War II FPSstore.steampowered.com/app/30/Distribution: $4.99 on Steam, free mod for Half-Life owners
Performance: Probably runs on everything
I've never played this, but I imagine it plays like the Source version, which is to say mildly entertaining.
Available modes: Conquest
Armagetron Tron clonewww.armagetronad.net/Distribution: Free Download
Performance: Probably runs on everything
A Tron game that would be probably be retarded to play as a LAN game, but it's pretty fun.
Available modes: Tron
Counter-Strike: Condition-Zero round-based tactical FPSstore.steampowered.com/app/80/Distribution: $9.99 on Steam
Performance: Probably runs on everything
A graphics update to Counter-Strike that also changes the weapon performance slightly, adds more default maps and a riot shield. Arguably the hardest version of Counter-Strike to play due to the unforgiving ballistics.
Available modes: Hostage rescue, bomb defusal, custom map game modes
Call of Duty World War II FPSstore.steampowered.com/app/2620/Distribution: $19.99 on Steam
Performance: Probably runs on everything
I've never actually played this, but according to Curtis, it plays exactly the same as any of the newer Call of Duty games. The graphics are just old.
Available modes: Deathmatch, team deathmatch, probably some other ones
Sauerbraten (Cube 2) twitch FPSsauerbraten.org/Distribution: Free Download
Performance: Probably runs on everything
A Quake/Unreal knockoff with hilarious sound effects and stupidly fast gameplay.
Available modes: I only ever played deathmatch but I think it has more
Counter-Strike: Source Round-based tactical FPSwww.counter-strike.net/Distribution: $19.99 on Steam
Performance: Any remotely recent graphics card will probably run it
A port of Counter-Strike to the Source engine. Major graphics update.
Available modes: Hostage rescue, bomb defusal, custom map game modes
Day of Defeat: Source World War II FPSwww.dayofdefeat.com/Distribution: $9.95 on Steam
Performance: Any remotely recent graphics card will probably run it
I used to play this with Forest an awful lot.
Available modes: Conquest
Age of Empires III imperial RTSwww.ageofempires3.com/Distribution: Shared copy
Performance: Any remotely recent graphics card will probably run it
The only RTS I was remotely good at.
Available modes: Skirmish and some other mode but I'm pretty sure they're the same thing
Synergy Half-Life 2 co-op modsynergymod.net/Distribution: Free mod for Half-Life 2 owners
Performance: Any remotely recent graphics card will probably run it
You essentially play through Half-Life 2 and it's episodes co-operatively. I played through the whole goddamn thing with Matt. Fuck that took forever.
Available modes: co-op
Garry's Mod physics sandboxwww.garrysmod.com/Distribution: $9.99 on Steam
Performance: Any remotely recent graphics card will probably run it
This would be lol.
Available modes: Sandbox, custom LUA game modes
Battlefield 2 large-scale modern FPSwww.ea.com/games/battlefield-2-complete-collectionDistribution: Shared copy
Performance: Requires a moderately decent DX9 card
Best with enough people to play in squads with commanders, but it has a co-op mode against the hilariously retarded bots.
Available modes: Conquest, co-op (conquest vs. bots)
Team Fortress 2 team-oriented FPSwww.teamfortress.com/Distribution: $19.99 on Steam
Performance: Requires a moderately decent DX9 card
I haven't played this in forever, but it's popular for good reason.
Available modes: I can't remember, there's a few of them
Call of Duty 4 modern FPSwww.activision.com/index.html#gamepage|en_US|gameId:COD4ModWar&brandId:CoDDistribution: Shared copy
Performance: Requires a moderately decent DX9 card
A tight FPS suitable for LAN play.
Available modes: Deathmatch, team deathmatch, headquarters, domination, search and destroy
There's probably shit I'm forgetting.