Got to be Elton John! Everytime I hear him, I want to burst out laughing. Interestingly, the first time I heard Elton sing, I said to myself, "This guy's been listening to Jose Feliciano", which makes Elton a copy of a copy because Jose, himself, wasn't singing in his natural accent i.e. when he spoke - back in the late 60s - he had a pronounced latin accent.

p.s. the similarity in their voices becomes very apparent when Jose sings an Elton John composition.