If I had it my way, I would take the anime and chop it down to the necessary parts. I would speedup parts and take out lots of clips that were just unnecessary such as the long pauses where you see everyones faces going "oooo" "aaaaaaa" or the uber long charge up times that obviously weren't there in the manga.
There is someone who does this. The project is called "One Pace", just google it.
For me though, even when condensed like this, the anime is just too bad to enjoy. .__."
The only good thing about it is the voice acting, which makes me care even for characters I don't like.
E.g. that scene between Kin'emon and Momonosuke, when they finally meet up on Punk Hazard. xD
I don't like either of them, but when I watched that scene in the anime, I was still moved, because they got the emotions across so well.
The animation, on the other hand... no. Just no. T__T
It's very noticeable that they are trying to save money on the painting and animation, but it just doesn't work out (for me, at least). One of the amazing things about the manga is how you can look at the characters and understand the way they feel (which I think is part of the reason that ambiguous characters whose feelings we aren't supposed to know yet, like Law or Corazon often have their faces hidden, their eyes in the shadow or something like that).
The anime just doesn't manage to catch the atmosphere and expression of the manga because it isn't as well-painted. All of the filler parts that even seem out of character at times really don't help this.
Watching it now just makes me cry, thinking: "OMG, what have they made of that absolutely awesome story they have been given?! It just feels like a cheap cash-grab!"
Though, way back when I first got into One Piece, it was through the anime, which first aired on german tv back then. I think I watched it until Alabasta (?)... but as far as I can remember, it by far wasn't as bad as it is now? Might just be nostalgic memories, though.
Around Water 7 I started reading the manga and from about Thriller Bark on, I have only tried to watch the anime a few times, but as it is right now, I am extremely disappointed. The Dressrosa arc in the manga is incredible, surely you could make a good anime adaption out of it! But what they are making doesn't even come close to the quality of the original. :/