"The Fastest Man Alive" is a phrase
DC Comics has used throughout its existence to announce its trademark
speedster character
The Flash. The first Flash was
Jay Garrick from the
1940s until
1956.
Barry Allen recieved the title when Jay went into semi-retirement, and Allen was the Fastest Man Alive until
1985 when he merged into the
Speed Force and became one with the
Other Side of the Light. Next to carry the title is
Wally West who was Allen's nephew.
There has always been an ongoing feud between fans of The Flash and those of Superman. A race was held once between Barry Allen and Supes. The Flash won, but there were complications during the race which question its validity. Maybe someday there will be a rematch.