Most badass Sharingan user

[SaskeUchi]

I agree with you.

Kakashi just came with PS within 10 mins after getting merely two ms.

Sasuke couldn't awake his PS until he got Rinnegan

Madara who was known to be a god awaken PS after getting ems.

Even itachi couldn't awake PS with ms.

So its safe to assume that kakashi is above all uchihas.

Are you reading the manga ?!
Sasuke awakened PS when he was making Susanoo and Kyubi with Naruto

 

[Djokovic]

The answer is Kakashi Hatake (after itachi)

Why?

madara was failed, couldn't even detect BZ and fodderized
Sasuke can't even hit kaguya single time instead caught in her dimension, saved thanks to sakura and obito
plot runs for many chapters but once a fodder always a fodder
obito had potential but he didn't had much power to show some cool stuff
then kakashi came, in less than 2 chapters he stomped kaguya completely!!!
what an excellent display to exploit sharingans and susano!!!
it was what we call a pro fighter!!
sasuke face was literally fill with jealousy at that time you can check it XD

Spoiler

You must be registered for see images

You must be registered for see links