First of all, don't come in here spewing nonsense like one word answers. Please have logic/reason of proof to counter my points. On to the thread.
Vs Itachi
Im going to break these 2 down in 2 catagories: first being strengths, second being why I think kakashi can pretty much counter itachi.
1.Ninjutsu- Tie- Aside from the obvious Uchiha moves like susanoo and amateratsu and kakashis kamui, I think these 2 are even here. While itachi may possess superior hand seal speed, kakashi has a much wider range of jutsu at his disposal.
2.Genjutsu- Itachi-obviously. However, if they had fought again, there is a reason why I think kakashi can nullify tsyukuomi. I'll explain it in part 2.
3.Taijutsu- Tie- While itachi has proven that his Taijutsu is a force to be reckoned with, I feel kakashis Taijutsu is severely underrated. I mean seriously...he fought Hidan with a kunai WHILE avoiding kakuzus masks.
4. Intellect-Tie- Both have proved to be the 2 most intellectual ninjas we have seen. I don't think either is smarter than the other. The winner of this fight needs something more. (Data book 3 backs up my first 4 points, so no arguing those.)
Here's why I think kakashi could win
When fighting most opponents, itachi likes to use first what he does best.....Genjutsu. While he incapacitated kakashi the first time with it, I don't think it would work on him again. The reason being: the same jutsu doesn't work twice on kakashi....he's too smart for that. He even told zabuza that and proved it to him. When kakashi fought the itachi clone in the anime, he distracted him and sent out a clone in his place which got caught in Genjutsu to no avail. I think this would work in a battle against the real itachi for 2 reasons: itachis fading eyesight and kakashis skill at making clones in combat. He even made a clone right in front of 2 paths of pain, a rinnegan user, and went completely undetected. Another notable comment to back my claim, chojis father even said kakashi always makes a clone toto test his opponents abilities first.
Kamui vs amateratsu/susanoo
I think kamui is an effective against both of these but I'll start with amateratsu. While the flames are deadly to anyone who comes in contact with it, I can gather one thing from this jutsus usage: it burns slowly. We've even seen 2 people use substitutions and one get his hand surgically removed before it caused any damage. Im pretty sure kakashi can kamui any fire that gets on him. We've seen his precise control over kamui in his fight against Tobi. The question is can he kamui amateratsu? If can kamui rasengans, lightning infused kunai and susanoos arrow , im sure he can kamui amateratsu.
We know that itachis susanoo boasts to weapons of legend: the yata mirror and the blade of totsuka. Since itachi incorporated them into his susanoo, I think it's safe to say they are the same composition...and you know what that means. If he kamui susanoo arrow, I sure he can use it on the objects or susanoo itself leaving itachi wide open for rakiri. Yata mirror isn't deflecting a t/s attack.
Final blow: kakashis rakiri. Itachi won't be able to dodge because of exhaustion and deteriorating eyesight. He can't counter this stronger faster version like he did sasukes. Not to mention kakashis has a good sharingan eye.
Thoughts?