The uchiha clan had a history of getting there ass kicked by the descendants of Ashura so obviously its the Uzumaki clan.
If anything, Hashirama beating Madara had more to do with Hashirama's own unique powers rather than Asura's influence.
Obito pretty much plowed Kushina behind Minato's back.
Shisui was a monster and was eliminated from the story because he's just too OP.
Sasuke whooped Naruto's whiskered behind at the VOTE, and it took two power-ups from the Nine-tails for Naruto to catch up to the Sharingan's power. The second fight was a win for Naruto I'll admit.
Don't even get me started on Indra himself, if he was able to draw with Asura with simply the Mangekyo Sharingan then that says something about Asura himself.
But in all seriousness, the Senju was only considered the strongest clan once Hashirama was able to use the Wood-Style. Before that, I'm pretty sure the Uchiha and Senju were even.