Wayne Gretzky has scored the most NHL goals. He has 894 goals.
MANY MANY players have scored 3 goals in a game. It's called a "hat trick."
Bobby Hull - 604 goals
243 goals scored in NHL hockey
The most goals scored in a single hockey game by a player was 7 goals. This record is held by Joe Malone. He scored 7 goals on January 31st 1920 while playing for the Hamilton tigers.
Alexander Ovechcin(2006 6 goals)
A hat trick
Any 3 goals, or more, scored by the same player in one hockey game is called a hat trick. Unofficially, 6 goals by the same player in one hockey game is called a double hat trick, but is a rarely accomplished feat in professional hockey.
Texas Hat Trick