I thought Bleach was great up until the end of the Soul Society arc...you know, when you-know-who has that awesome moment when he absolutely owns you-know-who-else with his f'n finger, even stopping his power theme mid-note.
It had a good build, great humour ("Spirits are always with yooouuu~!"), decent characters (with GREAT characters once you get to SS and take the Captains into account) and a very well made system of protecting people's power to the viewer's eyes - i.e. if somebody is strong, they let you know, and make sure he doesn't do anything weak-like!
(noticed that when i realised it was my main issue with the second filler arc - more about it in a bit)
I thought the Bount arc was pretty cool when it started, like Hybrid said, but then it kinda lost some of it's quality for reasons that i can't really recall since i watched it more than a year ago.
Then you back to manga stuff (which i don't read btw) and because of how the Bount arc ended nothing is really changed from the end of the SS arc.
A couple of pretty awesome stuff happen during the first few eps, like
(i really recommend you don't click this if you haven't watched everything there is to watch yet... )
and it keeps chucking along nicely with good, interesting story and typical Bleach RANDOM~! humour.
Then they get to a bit where the story demands they spent some time doing nothing and you get 4-5 of the worst episodes i've ever seen (cake episode, anyone?), but then they go fully into the next part of the story and that's where it starts really getting messy.
Problem was that at this point they're apparently really catching up to the manga and they degenerate into what Hybrid described a couple of posts ago - 25 min eps. with 5 mins. of actuall story advancment and everything is flashbacked/repeated at least 3 times.
That being said, they still put out some pretty awesome episodes every now and then, especially towards the end
This goes on until they go off into another filler arc
This second filler arc i didn't like very much. It had a good main bad guy, but was mostly just filled with annoying, naive characters who were just whining all the time.
My main problem was that power issue though
My point is that when you watch the canon stuff, everyone has a specific rank in power and is very well protected within his rank, so that you know where he stands. Fillers (or should i say, poorly-written fillers) tend to mess that rank up. It's not some obsession with canon, it's just a matter of quality and consistency - well-written, consistent fillers, i don't have any issue with.
On the other hand, extending stuff makes even well-written material seem boring and repetitive, so i'm not complaining about fillers much - this was an exception - and i just know to ignore them when it comes to the big picture.
Btw, now it's back to the main story and it's getting pretty good again.