That would be the great Gordie Howe who played at the ripe age of 51. The next man on the list would be Chris Chelios who played until age 47. Both spent the majority of their careers with the Detroit Red Wings.
The oldest current player is Chris Chelios. I am guessing at the all-time oldest player to be Gordie Howe.
Roy "Shrimp" Worters at 5'3" tall, the shortest player ever to play in the NHL
Nathan Gerbe of the Buffalo Sabres
play hockey for what ever team that drafted them