I respect who disagrees with me, everyone gave valids arguments, but this is a fight we will never see happening, just in our minds.
In my opinion:
Kakashi vs Mei: Mei is very underrated IMO, but kakahsi beats her and i don't feel like i want to explain since it's kind of obvious.
Kakashi vs Tsunade: Tsunade is very strong and average in speed, but kakashi can dodge her atacks due to sharingan and snip-shot
Kakashi vs Gaara: If gaara uses sand tsunami kakashi goes to the other dimension, if gaara starts defensive in his shell he gets kamui-ass raped.
Kakashi vs Oonoki: I think oonoki is too slow to avoid kamui.
Kakashi vs A: The hardest match for kakashi, kakashi would start with clones to learn about his abilities, he would out-smart him definitely and kamui-snip shot (kakashi takes 5/10)
AND THE ONES WHO SAY KAKASHI CAN USE 6 KAMUIS ONLY WITH KURAMA'S CHAKRA, READ THE THREAD PLEASE, KAKASHI CAN USE 13 JUTSUS (WICH 6 ARE KAMUI) WITHOUT KURAMA'S CHAKRA