It depends. How many can we afford to hire? We can't hire everyone, unless they're going on their own quests and earning their own keep. In that case, they might as well found their own guild.
Nana and Jeanette have obvious combat uses, as do Spork and Pashtu. Driinka would be useful in repairing and rebuilding the guildhouse. Null is interesting in that upkeep would be low, but what skills does she have? Madame Evil sounds like a hard sell, considering we're currently going after a particularly annoying kung-fu zombie.