I do like reading manga, but I tend to prefer anime-versions when it's the fighting-heavy shounen type of story - all that dynamic motion looks awesome when animated! The same goes for One Piece; I follow the anime, rather than the manga. I do own the first 7 or so volumes of the Bleach-manga, and they are neat. I might give it another shot sometime.
But you are SO RIGHT about his decision to keep going and keep cramming new villains and stuff into the storyline. It's like, YOU BEAT AIZEN! YOU BEAT THE DUDE ASPIRING TO BE A GOD! Where the heck do you even GO from there? D: One Piece gets away with continuing after they have beaten the snot out of the dude who is literally god, but they took an entirely different approach to it.
But if we're speaking of Tite Kubo, I have to say I actually like his earlier work, Zombie Powder. It had an interesting world, the same level of action as Bleach - and best of all, it's only four volumes long. Unfinished, yes, because it got canned, but with only 4 volumes, he never had time to derail his own storyline.