"My name is Barry Allen and I’m the fastest man alive." Sometimes.
Despite reminding us regularly of his claim to fame, the Flash hasn't always been the Fastest Man Alive, well, on the CW show at least.
That may change now that Barry has entered the Speed Force and gained a better mastery of it's power, but over the show's first two seasons, the Flash was regularly outran by a number of speedsters who had a better handle on their abilities.
1. The Reverse Flash
In the guise of Dr Harrison Wells, Eobard Thawne worked hard throughout Season One to enhance Barry's speed, hoping to use it for his own gain and return home to his own time.
With the help of the Tachyon Accerelator, the Reverse Flash proved himself to be faster than Barry time and time again, who couldn't defeat him initially without the help of Firestorm and Arrow.
Just after Barry finally learned how to match the Reverse Flash's speed, Zoom crashed onto Earth One and proved himself to be faster than any speedster the Flash had encountered before.
By stealing kinetic energy from every speedster he encountered, Hunter Zolomon's abilities grew exponentially, to the point where he could take on the Flash with ease, even paralysing him at one point just to send a message to the rest of Central City.
However, things changed by the time Season Two ended; Barry's newfound mastery of the Speed Force helped him become Zoom's equal and eventually win the day thanks to his heroic and noble self sacrifice.
It makes sense that Barry's most deadly enemies are faster than him, but what about the regular villain of the week?
In Season Two, Caitlin's former colleague Eliza Harmon replicates the Velocity 9 formula to enhance her speed, but the drug has unforeseen effects that damage her mind. Eliza becomes schizophrenic and develops an addiction to the serum, which soon leads to a clash with Barry.
As a result of using abusing Velocity 9, Trajectory becomes much faster than the Flash, which ultimately proves to be her downfall. After she takes one hit too many, Eliza's speed begins to increase to the point where her body can no longer handle it, wearing out her cells at a molecular level until she disintegrates into nothing.
4. The Turtle
If you can't outrun the Flash, just slow him down until you can! That's what Russell Glosson did after the particle accelerator gave him the ability to absorb kinetic energy around him, leaving everyone else almost motionless.
Technically, the Turtle isn't a speedster, but his power gave the impression that he was moving at super-speed, enabling him to perform heists in the blink of an eye.
The Flash eventually stopped Glosson by pushing through each individual pulse of energy that the Turtle gave out. He may have been slowed down to a snail's pace, but Barry was still the fastest man in the room, just not the fastest man alive.
Despite belonging to different networks at the time, Supergirl and The Flash successfully teamed up for the fan favourite episode "World's Finest" after Barry accidentally created a breach to Kara's Earth.
The writers refreshingly chose to avoid any conflict between the two, instead setting the heroes up as friends and perhaps even more, but there was still plenty of competition between them both at the end.
In order for Barry to return home, the Flash and Supergirl had to build up speed in order to create a breach, so the two decided to race in order to spur each other on. While no overall winner was crowned, the two seemed to be neck and neck for the majority of the competition, which means there's a strong chance that Kara could have ended up beating Barry.
Now that the two heroes will be reunited in the annual CW crossover, we hope that the Flash and Supergirl will race once again and this time, there must be a definitive winner to end this debate once and for all.