Fizz Buzz

for n in range(1, 101):
    line = ""
    if n%3 == 0:
        line = line + "Fizz"
    if n%5 == 0:
        line = line + "Buzz"

    if line:
        print line
    else:
        print n

An example of FizzBuzz being written from the ground up using Test-Driven Development and Ruby: https://www.youtube.com/watch?v=CHTep2zQVAc