I was a big fan on source multiplayer games. No more room in hell, zombie master, zombie panic, pirates vikings and knights II, zombie mods for Counter Strikes: Source and many others.
I miss that pure uninterrupted multiplayer fun with people writing stupid stuff in chat, without matchmaking and levels to grind, without stupid balance that aims at 50% win rate. And there was so much creativity!
I'm really happy Torn Banner is trying to keep the spirit of old multiplayer games alive. They did a really good job with Chivalry 2.