For me it's:
1. Naruto
2. One Piece
3. Bleach
Naruto takes it for me since im very fond of Kishimoto's designs (especially Akatsuki's) and art style, also his backgrounds are usually pretty detailed compared to alot of shounens, and the estetic design of the Rain & Cloud villages are fuckin wicked imo.
Rain Village
Cloud Village
Second is
One Piece, Oda is a master at drawing diffrent settings for the Strawhat's journey, and although most of it is win there's some shit in there too (imo ofc).
The character designs is pretty much 50-50, i always appreciate something unique, but sometimes the designs are just so goddamn fail that i have to do sum serious facepalming...
Alot of badass shit in there too though.
Bleach is third (obviously), mostly cuz of the lack of backgrounds, and Kubo himself has said that he doesn't really give a shit about backgrounds and tries to put focus on his characters instead, and as far as character designs and art goes it's really good, he's probably the best among the three when it comes to drawing bones and muscles.
But, as said, the lack of backgrounds, and the fact that pretty much every fight takes place in a empty desert or a plain hallway, really fucks with the overall experience.
@HentaiElder.
Yeah the Bleach sample-pics looks kinda plain compared to Naruto and OP's, but i didn't pick 'em, Bleach-Tards did :P
I made a thread in Narutofan's OP and Bleach sections for the tards ("fans") there to post their fave-spreads, and then i picked the best ones posted.