Oh, the dreams we have, imaginings of being smarter, stronger and faster. These have likely been with mankind since about the time we managed to wrangle fire. Personally, I've been partial to Superman for almost as far back as I can remember, but the first nickname I was tagged with as a child that came close was "Flash". Now, in my case, this had everything to do with my being considered a bright child and nothing to do with the fleet-footed fastest man alive. Still, many are the times I would have loved to be able to move at superhuman speed.
"The Flash" is a name shared by four (yes, four) DC comic book superhero characters, so it would certainly be tough to challenge his popularity. The original Flash made his first blurry appearance in Flash Comics #1 way back in January 1940, the creation of writer Gardner Fox and and artist Harry Lampert. The second incarnation of the Flash, Barry Allen, is generally considered the first hero of the Silver Age of comic books, starting his running about in 1956, and the superhero has remained one of DC's most popular ever since.
I'll simultaneously acknowledge and bypass the fact that, for many years, Superman's nigh-infinite powers easily made him a rival for the title of The Fastest Man Alive, but DC finally reined the Man of Steel in sufficiently to let The Flash have that to himself (Supes has so much else going for him, why not throw the guy a bone?) Nicknamed the Scarlet Speedster, each the Flash is the Flash because they all possess the power of super speed which includes the ability to run and move extremely fast for extended periods of time, use superhuman reflexes and seemingly make particular laws of physics their bitch. If you ever thought the Road Runner was impressive as he confounded the Coyote, you haven't lived. Sonic who? These guys turn time and space, and sometimes their own bodies, inside out.
Now, while it must be extremely fulfilling to be of super-fast service to their fellow man, I can't help but think that it would also be quite the joy to be able to get my Chinese food from Beijing on a whim, run across water or up and down the sides of buildings, outrace bullets, clean my house in the time of a few heartbeats or, perhaps best of the bunch, write novels faster than Mickey Spillane on crack.
I think the worst part of the powers would be waiting for things that couldn't be forced into a super-fast time frame. The Flash can vibrate the molecules of his body to pass through solid matter. He can also share the energy that fuels his power to provide speed to other things or people. So what happens when, instead of running through a wall, he decides to use a door at mach 4? I think there'd be a tremendous wind in a room and that's assuming the structure of the door could even hold up without the whole thing flying apart. That's fine when you want to storm the mafia hideout, but not for visiting your mom.
Imagine the tedium waiting in a long line at the store. There are only two cashiers open and one of them is waiting on a supervisor to clear up a problem. The people ahead of you are writing checks, but don't start until everything's done being bagged and some of them have items that need price checks. Meanwhile, your mind is in an accelerated time frame, thinking of thousands of different things that you need to get to doing if only you could ever get out of this line. You're an accelerated metabolism in a crock-pot world. Your every human interaction involves waiting for people to reach one of a dozen variant conclusions you reached before the first sentence of the conversation was finished.
AAAAAAAAAAGGGGGGH!!! Unless you can develop the patience of a monk, running and writing and other solitary activities might be the only joys left to you.
No wonder the comic speedsters spend so much time, relativisitcally speaking, hanging out with each other. They're really the only ones who can relate to the experience of racing lightning while living in a slow-motion world. Being The Flash isn't just a heroic triumph over time and speed, but apparently over tedium-fueled insanity as well.