Back when I did regular LANs with friends in high school, we almost exclusively played AoE2 (and AoE2 HD when it came out). Later in the night as people crashed, the folks that stayed up later would play minecraft and then sometimes me and my 1 tf2 friend would play mge (or arena 1v1 if i didn't want to set it up).
Me and my friends also played through a really small indie MORPG once, which is super fun. Some of them stayed up all night to finish it. It was a game I helped in the development process in (and engineered the sound/ made the music for) when I was like 13ish, and it is actually surprisingly decent on lan.
http://wukaworld.weebly.com/free-download.html
It wasn't originally a lan game, but I could probably hook you guys up with the server files that you would need to run it if you're ever interested.
Mainly AoE tho