Which is the best site to stream One Piece in the highest quality for free? The first episodes are so pixelated in the sites that I use

That's just because the early stuff was 480i. There are some upscaled versions available, but I'm not sure if anyone streams it.

Might be worth asking over on [email protected], but like the other one said: it's old. So, you may have to deal with it (unless your source is so bad that it's worse).

Piracy is bad. So i won't suggest you bad site like 9anime.pe or anix.to ... nope. Sorry but i won't do that.

Search for "One Pace", it might help to look at first episodes, because they upscale them.