2. The original TV Flash
The moment that The Flash finally graduated into the mainstream came when he headlined his first ever TV show. CBS' The Flash aired on screens in 1990 and starred John Wesley Shipp as the titular hero in an adventure that was very cinematic for television at the time, and very much inspired by the successes of the Superman and Batman movies.
While the series didn't last beyond one season, it was a great adaptation of the character. Barry Allen was struck by lightning on that fateful night in his lab and developed super-speed as a result. He then saw this an opportunity to save a city in need of a hero, donning a red uniform with a lightning bolt symbol on its chest, and the rest was history.
The Flash we met in the series was pretty comic-accurate at the time, and he possessed all of the abilities that the Scarlet Speedster is known for, including the speed, durability, and connection to the Speed Force. He could also absorb electricity from nearby sources and, as we saw during his return 30 years later in the Arrowverse's Crisis On Infinite Earths crossover, he can also momentarily steal another speedster's speed.
This Flash has seen it all and, throwing in all of the abilities he has picked up over the years, this makes him one of the most powerful we've ever seen in live-action.