The Flash can be easily considered as the fastest superhero..but there can be other heroes that can be compared to the flash and can even beat the flash.
The marvel version of flash can run with the speed of light thanks to exposure to isotope E. Pretty much equals flash..but loses out in the cool of "The flash".
Now this guy is the fastest of the lot ..travelling through light years in seconds. Apart from being incredibly strong and brilliant reflexes.
This x-man may come as a surprise,but what is speed,the distance Yu cover in time.Now Nightcrawler can travel from literally any point to another in seconds.
The original super beings..mattari is also super strong and could fly..but by focusing on speed..he sacrificed his flight for his craze on super speed.
5.Goku- Instant transmission. Done!
(Now this is anime,but nevertheless Goku is one of the most followed superheroes)