Sports Illustrated in the US recently did an article in their NBA preview issue where they listed the best basketball players of all-time by height.
So for example, Michael Jordan was the best 6'6" player ever, Bill Russell the best 6'10" player, Allen Iverson the best 6'0" player ever.

Let's come up with a list for fighters (we'll use the heights listed on Boxrec for the sake of continuity):

7'0"- Nicolay Valuev
6'11"-
6'10"-
6'9"-
6'8"-
6'7"-
6'6"-
6'5"-
6'4"-
6'3"- Muhammad Ali
6'2"- Joe Louis
6'1"-
6'0"-
5'11"- Ray Robinson
5'10"- Ray Leonard
5'9"-
5'8"-
5'7"- Roberto Duran
5'6"-
5'5"- Henry Armstrong
5'4"-
5'3"-
5'2"-
5'1"-
5'0"-

I filled in some of the obvious ones. Let's see how many we can figure out and fill in.