Edit It was MajorMud. I found a relatively recent article where a guy researched the BBS some.

That was my first one too! They only allowed so many commands per day (100?) unless you paid $15/mo

Later I found the PvP MUDs and ended up playing a custom Godwars variant (Chaosium/Static Chaos) for years. I still know some of the people that I met in that game.