I've had/have Andros, LQs, Centruroides, Opisthalmus, Heterometrus, pandinus, hadrurus, babycurus, isometrus, parabuthus, Vaejovis, and a couple more.
So basically all the popular species.
I want something different.
Tityus?
I also have my eye on a Orthochirus scrobiculosus JA is selling. Those things are TINY though. They use their metasoma to triangulate though which is cool.