My first introduction to a speedster in comics came around 1952 with Johnny Quick, who's coyly referenced in "Flash" through the mathematical formula which gave him velocity and through the character Jesse Quick, his daughter in comic books. I vividly remember when the Barry Allen Flash came into being in 1956, ushering in the Silver Age of superheroes. He fought DC's strongest line-up of villains -- Captain Cold, the Mirror Master, Captain Boomerang, etc.
Carmine Infantino provided cool, modernistic art for action adventures written for early adolescents in a cool, modernistic style. Iris West graduated from Barry Allen's fiancee to "just good friend". Emotional temperature stayed low, as it did in the revived and revised Green Lantern, Atom, and Hawkman-Hawkgirl stories.
DC characterization remained equally cool and mostly vestigial. At one point a "Justice League of America" script had Wonder Woman as the monthly rotational chair of the group; the printed comic had Batman taking the role without a single word changed in dialogue. Try that after the Dark Knight revolution...
The 1990 "Flash" series starring John Wesley Shipp remained truer to old DC than not. By contrast, the current "Flash" has given us two seasons of complex, charming characters in complicated story arcs firmly based in human relations, not just hero-villain interaction. Grant Gustin's winsome Barry Allen anchors the stories to a slightly goofy, noble, flawed individual who screws up a lot and tries to bear the weight of his world on too slender shoulders.
His questionable choices at the end of Seasons One and Two have had huge consequences for the folks in this series, and have remolded the entire Arrowverse, particularly the "Arrow" series. The story arc for Season Three includes an alien invasion crossover with "Arrow", "Supergirl", and "Legends of Tomorrow". The writers top even that with an additional "Supergirl".crossover in musical format.
I thought the Season Five ending to the darker, fiercer "Arrow" wrenched my emotions. The finale to "Flash" Season Three took me on an open-mouthed roller coaster ride with characters I have come to love, respect, and enjoy on the deepest television level.
Themes exploring the meanings of family, responsibility for personal actions, and defeating the savage burden of despair have cornerstoned "Flash" from its first episode. The continuing characters have expanded remarkably since the beginning and each one continues to blossom even more fully this time around.
Special mention needs to go to Tom Cavanagh who has played a different Harrison Wells in each season. He brings more than one to this storyline, replacing the austere prior Wellses with a jiving ditz who still manages to rise to heroic stature when his team needs him.