Best Lan-Games of all time

Rise of Nations , AoE2

Crawl!! fo sho (more of a 1 machine 4 players deal but you should be able to use multiple keyboards

Sonic all star racing for some kart fun!

I don't know if you're referring to the original Unreal or Tournament (2004), but I can strongly recommend the latter two. It's worth playing them for the legendary "Megakill!" etc. alone.

I'm still annoyed that we can't get them on Steam in Germany, but it was not that diffcult to get your hands on a boxed copy (at least when it was new).

Rocket League, trust me

Try Overcooked.
Yogscast demonstration. (The order is a bit mixed up. Mind the video dates)

Command & Conquer, Serious Sam, No one lives forever, Soldier of Fortune ... those were the days.

As for still enjoyable today, i´ll repeat Serious Sam, the absolute boozer amongst Co-op games!

Rainbow Six: Vegas 1-2, Sacred Gold, you can check this:
LAN Game List

I was gonna say Atomic Bomberman but that doesn't even work properly on Windows 7 so 10 is no doubt impossible.

Prey classic, definitely.

Starcraft

Liero.

Nothing says everlasting friendship like headshots and teabagging. :)

Also, I can't imagine RTS games are fun when drunk, but what do I know?

Finally, is it possible to link up and play Sonic & All-Stars Racing Transformed? I think mindless = good time. That's a game you can have fun with, and people can opt in and out throughout the evening.

StarCraft, Diablo II, Magicka 1 & 2, Alien Swarm: Reactive Drop, Helldivers, Heroes III, Total Annihilation, UT 2004 & III, Jazz Jackrabbit 2. Those come to my mind and those I recommend. Also, Bloody Trapland in small doses was quite funny to play with my gf and brother. Depending on how much beer you plan to drink I would consider NOT playing RTS games. ;)

Monster Truck Madness 2 - Play Rumble; It's King of the Hill with monster trucks.
Worms Armageddon
OpenRA
Doom/Doom II/Hexen - Through GZDoom - You'll need to obtain the .wad files, though maybe one of you has the games somewhere
Diablo I & II
Sacred
Eggnogg+ - It's like Nidhogg, but free. (Click download, then click "No thanks, just take me to the downloads").
Gang Beasts
SpeedRunners

Bonus:
Controllers & emulators (and a tv or large monitor), to play your favorite old N64 games (Or just grab the consoles/controllers/games that you already have)
Goldeneye, Perfect Dark, Mario Party, Mario Kart, Mario Tennis, Diddy Kong Racing, Wave Race, Wayne Gretzky's 3D Hockey
Fuzion Frenzy on Xbox is also a lot of fun to play.

Unreal Tournament for sure.. ;) And also Worms and Colin McRae Rally's :)

Bulanci. Dont known? Try it.. xD

MTG!!

Gang Beasts
NSFW (strong language)

my lan friends are more into co-op. we've had a lot of fun with killing floor, left 4 dead 1 & 2, magicka, civilization (any version), sanctum, dungeon defenders, serious sam (all of them except maybe not 2), borderlands 1 & 2, terraria, half-life 1 & 2 deathmatch, the ship, star wars jedi knight jedi academy

Serious Sam and the C.S. series

We always had a lot of fun with Soldat at our LAN parties. Plus it's free. Chivalry is another good one. Natural Selection 2 is a nice cross between FPS and RTS, but there is a learning curve so maybe not best if noone has played it before.