6. Garry Kasparov – IQ 194

Garry Kasparov is without a doubt, the greatest chess player of all times. Between his professional debut in 1986 and the end of his career in 2005, Kasparov was ranked #1 for 225 out of a total of 228 months, the greatest form ever recorded for a chess grandmaster. Kasparov has been viewed as quite a prodigy over the years, having his fair share of international acclaim not only for his competitive form, but also for playing competitive matches and winning against advanced chess machines like IBM’s Deep Blue computer.