Alright. Let's do this correctly.
Itachi: Despite being the fan favorite most of his arsenal is useless here. All of his genjutsu (his whole mo) gets broken by the other three with ease,that's just hown 3t sharingan works.So genjutsu is out of the question.
His fire techniques get owed by elemental superiority(kakashi) or flat out overpowered(obito). The only one he might beat in this category is sasuke(sasuke needs curse mark to over power him and his hand seal speed is inferior). He is however a clone user thus he can get the drop on unsuspecting opponents. But his stamina is absolute garbage. So a long drawn out fight isn't what he wants, sadly that's what this will end up being.
Taijutsu he's again superior to sasuke and through kakashi obito. But his clone stalemated against kakashi's clone, so we can't put him above Kakashi.
The length of the fight and his lack of 1 shot techs (no ms/no Genjutsu) will be his downfall.
Sasuke: His genjutsu is garbage, no questions asked, stated by danzo. Compared to the likes of itachi, (portrayed to be better by hype and feats) and to the likes of obito(keeping perfect jins in the trap) hes trash. Kakashi while not having that many genjutsu feats(made zabuza second guess his whole life) has went up against the aforementioned ppl and fared for the most part well, unlike this mug. But alas 3t genjutsu is useless here. Sharingan breaks it.
Ninjutsu, most of sasuke's better feats come from his curse mark. His fire techniques is getting flat out overpowered by Itachi(that's a shame), obito and Kakashi (elemental superiority) his handseal speed is the slowest out of the four and his lightning techs are inferior to kakashi's. So unless he gets a Kirin off (no ama) it's looking bleak. But chidori (despite never doing it in manga canon) is a potential 1 shot.
Taijutsu:he's ok. He does have chidori nagashi going for him but again he's already been bested by a ailing itachi where others stalemated.not to mention his ok ish stamina.
Ninjataijutsu is great but his okish stamina inferior ninjutsu will be his bane.
Obito. His genjutsu feats are fantastic, but 3t cancels genjutsu so we skipping it (besides most of it was already mentioned)
Ninjutsu:the strongest of the bunch, but not the most diverse. His techs required only 1 seal and their size dwarfs even tailed beasts. Not to mention hashirama cells giving him access to earth and water techniques Which would also scale up.
Taijutsu:this is tricky. The bulk of his feats come from kamui and when he didn't use it he got lol'd at by kakashi. So he might be better than Sasuke but that's it. His stamina however is remarkable. He's in it 4 the long haul.
Cqc might not be the best but his ninjutsu will keep you at bay, and he isn't going anywhere soon.
Kakashi. His genjutsu is okish(putting anbu in the trap) but again a non factor.
Ninjutsu. He's the most versatile (5 elements) but not the most powerful. He has a jutsu for nearly every situation and his clones game is superior to itachi's. But power wise he's getting beat out by obito, even with element superiority. But his raikiri can easily end him (like manga cannon)
Taijutsu, he stalmated with itachi and bested obito. He also bested sasuke, so it's between him and itachi, but like obito his stamina is well, compared to sasuke and itachi, ridiculous. Fighting for 2 full days straight.
Above average all round with stamina to boot. Has 1 shot techs.
So IMHO it's between obito or kakashi, but leaning more towards obito simply due to superior aoe.
Obito>=kakashi> itachi> Sasuke.
