Jesus, even i can play it almost lagg free.
The only lagg i get is because of my crappy internet.
Lucky person. :/
Hey, who-hoo. New, updated list.
-r_maxdlights 8
-r_dynamic 0
-fog_enable 0
-r_3dsky 0
-mat_grain_enable 0
-mat_disable_bloom 1
-r_shadows 0
-r_decals 10
-r_waterDrawreflection 0
-r_waterDrawrefraction 0
Ugh.
Edit: I found the autoexec.cfg (It was in steamapps/common/Alien Swarm/swarm), and put all of these in there, but it didn't seem to work. When I went into the console and started typing any of the commands, the suggestions box came up with the command, folowed by the variable I don't want. Such as, r_3dsky 1 instead of r_3dsky 0.