Bam Bam Bigelow
He was the first agile big man in a land of giants. WWF fans were used to seeing giants like Big John Studd, King Kong Bundy and Andre the Giant who could barely move. Bigelow was the first guy with massive size who could also put together a wonderful match as well. He could wrestle with guys bigger and smaller than him and make everyone look great.
A perfect example of this is the Main Event of WrestleMania 11 where he made Lawrence Taylor look like a seasoned pro. LT had no business in the main event, but Bigelow carried him through. Bam Bam was one of the best big men of all time and deserves this spot.