FizzBuzz using CL:FORMAT:
CL:FORMAT
(loop for i from 1 to 100 do (format t "~:[~:[~S~;Buzz~]~;Fizz~:[~;Buzz~]~]~%" (zerop (mod i 3)) (zerop (mod i 5)) i))
I tried to fit it all into the control string itself, but boy is that scary.