The early part of the series is where I believed Togashi was at his peak in terms of art work. For some reason I really loved his style at the point. Then, it went downhill, and with Hunter X Hunter it still is way too damn basic and lackluster.
Anyway, when I was still a fan of Yu Yu Hakusho (back up until the end of the first Dark Tournament), I do suppose that I preferred the series animated rather than in still manga form. Although I do actually enjoy the early chapters of Yusuke helping out others as he tries to gain redemption to return back to his body. Had some real heart in some of those stories.