What do you think 'One Piece' (the treasure) is?

LazySketcher

It's a dragon ball…

square

It's a swimsuit obviously.

Diamond Jozu

@LazySketcher:

It's a dragon ball…

So there is bound to be about 7 one pieces then?

noob

Gold, jewels, pearls, a bronze statue, a four leaf clover and the Rio Poneglyph!

30slak

I bet it's really Sabo.

(if it's the message of love or something like that i will f*cking burn all my manga pockets)

dazztopaz

i don't know where gol d. roger said that the thing he left is one piece,
still everyone called it one piece even whitebeard,but i am sure roger's crew (that we know so far) never said such a thing of "getting one piece",they never said yet never deny it,

my opinion,one piece is what roger's dreaming about,one piece is what roger acknowledge as "his treasure",doesn't mean it has to be real treasure like wealth, gold ext..
but i am pretty sure,,,beside it,rio poneglyph were there in raftel,

KaizokuJinbei

I often wondered if One Piece is the strawhat Luffy wears (also worn by Shanks and the Pirate King himself)

Firefist_Ace

Okay, definitely check out the original theory (link below,) but I'll summarize it here. Out of all the fan theories I've seen, this one has been the best.

So we all know that OP will not be some stupid thing like a crapload of treasure.

Roger's will wasn't his original will. It was inherited by him from someone over 800 years ago (when is 800 years ago? Yeah, the void century). It was originally the will of, yep, the Ancient kingdom (the AK).
The AK ruled the entire world, almost (just like the world government now, the douches). They had almost nothing in their way, except an issue.
As we know, the planet of OP contains four big seas (E/W/N/S) seperated by the grand line and the red line. This was a huge obstacle, preventing people from traveling between seas, thus preventing the AK's full prosperity as well.
So then came the project. Eliminating the Red Line and the Grand Line to fuse the 4 seas into a big ocean. The united ocean. This was the project, One Piece.

Not everyone liked it very much, of course. There was war, in which the AK was wiped out. The opposers, and the victors, declared themselves to be the World Government. They covered up the history of the AK, and the "One Piece" project was never heard again until Roger's final execution.

So OP, how will this be possible?

There are two areas in the entire world of OP that interconnect all four oceans. First is Reverse Mountain, the conjoint of the Red Line, the Grand Line, as well as all the oceans. There is also Fishman's Island/Mariejoa.

This is also why the weapons were created. The ultimate weapons (Poseidon, Pluton etc). A weapon to break through the red line… a weapon so powerful that it would be capable of doing so... that is why these were created.

And so, when Luffy finally learns of the true OP (thanks to Robin and the poneglyphs), he will enlist Shirahoshi to destroy the point at fishman's island and his crew will head towards Reverse Mountain after finding the weapons.

As well, after destroying a massive entity such as Reverse Mountain so suddenly, the impact will cause a phenomenal whirlpool in place of Reverse Mountain. And Reverse Mountain, this point that conjoins all four oceans, will naturally also have creatures from all four oceans. This section, the ocean that will now replace the mountain, will be known as the All Blue.

The Strawhat's Dreams
With this, over 6 of the Strawhat pirate's dreams will be fulfilled.
Luffy: now uniting all four oceans, he has literally become "the man who has the most freedom in the ocean," the Pirate King.
Sanji: well, now Sanji has found the All Blue
Nami: the entire ocean is free to sail, so drawing a world map isn't so impossible anymore
Franky: same as Nami. Now, Sunny can travel over the entire world
Robin: this was all because Robin found the true history of the Void Century
Brook: he can meet Laboon! It was impossible before because Reverse mountain was in the way, but now… well, it's not so impossible anymore.

ALL CREDIT GOES HERE.
http://mangahelpers.com/forum/showthread.php/2989520-The-Inherited-Will-One-Piece

Ordinary

@Firefist_Ace:

Stuff Stuff Stuff Stuff Stuff Stuff Stuff Stuff Stuff Stuff Stuff Stuff Copy Paste Copy Paste Copy Paste Stuff Stuff Stuff Stuff Stuff Stuff

You might want to see this thread right here in APForums itself. http://www.arlongpark.net/showthread.php?t=38205
It's posted by the same person actually, (Clue:Indonesia) and the thread is practically identical. So yeah, a lot of people have seen this awesome theory already.

Shadow_HaxOr

I think it's strawhat