The Sannin is my favourite group.
I love the Sannin and I think they are the most interesting team. The Sannin are powerful and legendary but not overpowered to the point where it becomes boring. They also don’t depend on kkg and asspull power ups. Tsunade is a senju/uzumaki but that doesn’t help her much as she still had to work and develop her own techniques and skills. Even orochimaru’s experiments on himself aren’t what make him deadly. The Sannin depend mostly on skill and hard work and that’s what makes them special.
It’s also refreshing to see a team where all the members are more or less equal and where the girl is not sidelined or treated as inferior to the boys.
I would much rather see Orochimaru vs Jiraiya than Madara vs Hashirama or Sasuke vs Naruto.