Turtles and Dark Warriors.
Turtles if you have decent funds and want to do more in the game once you cap. (dungeons, cc, tmq, so and so...)
Dark Warriors if you just want to pure PvE farm all the time.
Both are really good, one has potential and the other has purpose.
What about an ultimate with Kidbuu and some good cooldown gear
Ultimate Majin with 66% CD is epic. You just buff yourself, transforms into kidbuu and farm for 20 min. Than come back to normal form, buff again and turns into kidbuu.