Tiara, Abyss and kanan are the most common mods people use. Tiara edits the data folder/creates a custom pack file, which is mostly visual editing. Abyss and kanan edit memory, which can change how some things work mechanically. A lot of people choose combinations of them, or all three. One thing to avoid if you choose to use Abyss and kanan together is choosing to have some patch enabled on one or the other, but not both, if they do the same thing. This would mean enable Scouter/ShowCombatPower on either Abyss or kanan, but not on both as it could cause unintended things from happening.