Where would you rank the game in the series?
DaS3 > BB > DaS1 > DaS2 > DeS
This is from the point of view of someone who doesn't really care about the story/lore much.
I think it's got the most accomplished gameplay in the series, it offers the most challenge, it's got some of the best level design (you've got fewer areas looping around to earlier areas, but the areas themselves tend to be better: bigger, more nonlinear, more shortcuts, etc.) and remains really consistent throughout (I can't think of a single area that I don't like so far, and I think I've just got one more to see). You've got a great variety of enemies and bosses...
Speaking of the bosses, I really think they knocked it out of the park with this one. You have bosses that are just outstanding challenging fights that keep you on the edge of your seat the whole way through, like Pontiff Sullivan, Soul of Cinder, the Abyss Watchers, and the Nameless King (I've yet to beat this one though

).
You also have fights that are easier, but which still really wowed me because of the presentation, like Aldrich, Devourer of Gods, Lothric (that charged helm splitter attack that sends a shockwave across the entire room is so hype it's unreal), or the Dragon Slayer Armour. Champion Gundyr is also pretty cool, because I was expecting the same fight but then half way through he goes berserk instead of transforming and becomes super aggressive.
Then you have boss fights that rely on gimmicks like Yhorm, Wolnir, Curse-Rotted Greatwood, or the Deacons of the Deep. Those are a bit reminiscent of the DeS bosses, however they are more complex mechanically which makes them more fun to fight imho.
Finally there's the rest of the bosses that don't really do anything special but are still very well executed. I can't think of a single bad one (whereas I can for anf other game in the series).