Since One Piece began, Luffy's quest has always been to find Roger's treasure. Over time, such a goal proved loftier than he realized. In order to discover the map location of the island, one must collect all four poneglyphs and somehow translate them. Consequently, there are only a few crews in the world able to succeed.
Although Luffy is getting remarkably close to concluding his journey, there are many other anime characters that could hypothetically beat him there. Whether due to their higher intelligence, superior abilities, or better resources, these individuals have what it takes to become the next king of the pirates first.
There are few characters more capable of finding the One Piece than Fullmetal Alchemist's Father. In addition to nearly ascending as a god, he had an entire country's worth of soldiers that he could use in order to collect both poneglyph rubbings.
Granted, alchemists are not strong enough to defeat Big Mom or Kaido, though they wouldn't need to stay on Whole Cake Island or Wano to fight a prolonged war. With the rubbings in their position, the state's most studious linguists could translate their findings.
Hunter X Hunter's Palm may be far from the most powerful or intelligent character, though her nen ability allows her to bypass the need for poneglyphs or translators completely. Since she can scry virtually anything, she'd be able to get a perfect image of Laugh Tale and what Roger's treasure is.
Given that she is a member of the Hunter's Association, her colleagues would help her do the rest. Considering that finding treasure is part of what their organization does, it wouldn't take convincing for them to rally behind the cause.
8 Lelouch Could Hypnotize Rayleigh (Code Geass)
Code Geass' Lelouch has one of the most powerful hypnosis abilities in anime. It forces the subject to fulfill specific commands and will only relinquish them once the task is complete.
Given that Rayleigh is Roger's relatively high profile first mate, Lelouch would deduce that he knows where the One Piece is and use his ability on him accordingly. Considering that there is no evidence to suggest that haki protects one against hypnosis, it should work fairly well so long as Lelouch uses the right terminology.
The Demon King is one of the most powerful entities in the Seven Deadly Sins and easily commands its greatest armies. By raising his dreadful clan and unleashing them on the high seas, he could invade both Whole Cake Island and Wano, receiving their scrubbings with soldiers to spare.
Alternatively, the Demon King could instruct Fraudrin to infiltrate both islands for a much more bloodless solution. Once he collected the information needed, he could kidnap either Robin or Momonosuke to help him translate it.
6 Aizen's Zanpakuto Would Be Difficult To Counter (Bleach)
By himself, Bleach's Aizen would already be difficult to stop. He commands an organization of powerful Espada, plus the monsters of Hueco Mundo. When combined with his enormous spiritual pressure, there are few characters short of emperors themselves that might stand against him.
After procuring the poneglyph rubbings, Aizen would only need to find a translator and use his Zanpakuto to hypnotize them. This guarantees that the map they would give him in return is accurate and that nothing will impede his journey to Laugh Tale.
For all of Luffy's progress, Shanks is in a much better position to find Roger's treasure than he is. For example, he has been an emperor of the sea for a much longer time and even has connections within the Five Elders themselves.
Additionally, Shanks was a former member of Roger's crew who came alarmingly close to finding Laugh Tale before departing to take care of Buggy. Luffy's only advantage is that he has an active translator on his crew, although it's not even a guarantee that Shanks doesn't.
4 All For One Would Become Much Stronger En Route To The One Piece (My Hero Academia)
My Hero Academia's All For One might not start off strong enough to challenge the emperors, though he'd quickly be able to. Considering that he is able to hold multiple Quirks at once, it follows that the same would apply for Devil Fruits.
Should All For One visit Whole Cake Island first, he'd be able to capitalize on Big Mom's low mobility to steal her power. Granted, it still wouldn't be enough to defeat her, though it'd ensure that she couldn't call on Zeus or Prometheus as his villains make their escape.
Naruto's Minato was frequently regarded as the fastest shinobi alive. Since he could teleport from one tag to another with dazzling speed, there are no emperor pirates that would be able to stop his advance.
Although Katakuri's future sight might help him anticipate the Yellow Flash, he is almost never present in Big Mom's affairs unless explicitly summoned. As a result, Minato would have taken the rubbings and left long before he realized there was an intrusion. Minato could then return the rubbings to the Leaf, where the Nara and Yamanaka clans would help him understand them better.
2 Light Could Execute His Enemies Before Arriving To Islands (Death Note)
It would be insultingly easy for Death Note's Light Yagami to obtain the poneglyphs since his opponents are virtually handed to him on a silver platter. All he would need to do is look over the World Government's compiled list of Big Mom and Animal Kingdom bounties, then write them down in his notebook with their faces in mind.
For a translator, he'd just need to write that Robin helped him understand the poneglyphs before killing herself. This would solve his dilemma while ensuring she didn't still stand in his way.
1 Whitebeard Passed Up An Opportunity Roger Offered (One Piece)
Whitebeard had perhaps the most straightforward and honest way to obtain the One Piece. Since he was Roger's equal and friend throughout life, the man flagrantly offered him his treasure and his mantle as the king of the pirates.
Initially, Whitebeard refused since it would attract too much attention and that his family was more important. Should he find it as a matter of grave urgency, however, he could have obtained the One Piece faster than Shanks or Luffy would ever dream of.