I wouldn't say Einstein because person behind him was also important as he was . Ofc it was his wife . Facts proven that Einstein had lower knowledge from mathematics than he had from physic , and w/o her help , his biggest theory wouldn't even exist . Newest evidence suggests that Mileva's role in formulating the "Theory of Relativity" was significant.
From Scientists I would choose Alfred Nobel , from Compositors Beethoven , Bill Gates from businessmen . It's hard to take only one person , since u didn't defined the category .
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