Hot take, but I still think the best AC combat was the first one. AC3 had some really impressive takedowns and stuff, but I felt too powerful. In the prologue section I would just spend ages walking up to whole platoons of British soldiers and just murdering the hell out of them with ease. It was fun and impressive to watch, but just no challenge to it.
I've spent my entire gaming life waiting for a true, satisfying, cinematic swordfighting game. Lots of hack and slash, block and parry, plenty of visual flair. I want a Hollywood sword fight. And I can't believe that I'm still waiting for it all these years later. Yeah there are lots of games where you hit things with swords, but nothing where you actually get a solid steel on steel combat going. Possibly the closest to the feel of what I'm looking for remains AC1. It wasn't super deep, but that feeling of being surrounded by a bunch of foes, blocking their attacks, doing a fancy counter while the camera moved in... it was cinematic as hell. I just want that, but with more granular control than just "hold button and hit counter". But as a starting point, that was very much the feel of what a proper swashbuckling game would feel like.
It's weird that AC turned into this rambling franchise where you just massacre thousands every game. I've killed so many innocent roof sentries who were just trying to earn a quid, you know? I wish they had gone the other way, where you kill fewer people, but the fights are way more detailed and complicated and epic. But I feel that about many games, where they put quantity of kills above making them satisfying and meaningful.