Dark Souls 2 is a ridiculously good game, but I have to disagree here. I've felt as if the bosses have been mostly downhill since Demon's Souls. There are notable exceptions likeI thought Demon's did it best because most bosses had some sort of mechanic that needed to be understood.Arotorias, Fume Knight, Sinh, Ornstein & Smough, etc.
It seems most bosses now are wait for opening and then attack. Whereas I really enjoyed theOld Hero from Demon's because he was blind, but used hearing as his source to attack.
This has been my problem with boss designs in the series since Dark Souls 1 and why only the best of the best bosses in Dark Souls and beyond are the only ones I enjoy. The rest are nearly mindless and borderline boring.