You can search lists but they are all severely biassed. One list, giving Wayne Gretzky as their number one, has suspiciously all Canadians in the top ten. Gretzky is a Canadian former professional ice hockey player.
Others say Alex Ovechkin who made his National Hockey League (NHL) debut in 2005 with the Washington Capitals, He comes top of several lists. As for field hockey, we turn to India. Dhyan Chand, the Indian field hockey player is widely considered the best ever.