Someone local to me had launched a pay-for-membership based MajorBBS that had something like 16 phone lines in. MajorBBS was the only thing I had seen that could support so many users at once. This was around the time I had stopped running my own BBS, before college.
This meant it could offer an active chat room, and it had a MUD game that everyone loved, called TeleArena.
For me, TeleArena was fun because I'd write scripts that would automate playing the game for me when I wasn't there.