The closest anyone has ever gotten in predicting a perfect NCAA Basketball bracket, that is known publicly, is 55 right out of a possible 63. This was done by the winner of ESPN.com's NCAA Tournament Challenge in 2008. No better score could be found online or in any articles, but in 2010 an autistic 17-year-old high school student got his entire bracket right through the first 2 rounds of the tournament. Alex Herrman of the Chicago area had a perfect bracket all the way up to the Sweet Sixteen. But, he lost when Butler upset Syracuse, and finished poorly since he didn't get any of the Final Four teams right.
Statisticians, mathematicians, and sports experts have calculated that the odds of picking the perfect bracket are 9,223,372,036,854,775,808 to 1. Nobody has ever done it in the 27 years since the NCAA Tournament expanded to 64 teams in 1985.
2012 is the 28th year of the tournament, and after 2 rounds nobody had a perfect bracket in the ESPN Bracket Challenge, despite a record 6.45 million entries.