8. Ye Shiwen (female, swimming)
The 16-year-old Chinese swimmer stunned the world with two individual medley golds and many records - a world record and an Olympic record - in her Olympic debut. Ye improved the world record in the women's 400m individual medley by more than one second, all the more remarkable as she swam the last 50m in a faster time than U.S. 400m individual medley champion Ryan Lochte.