The Flash saving a city from a nuclear bomb - by carrying all of its people to safety, one or two at a time.Holy◊ crap.◊
Which by estimates means instead of the "hair's breadth short of the speed of light" the narrator says, instead Flash was moving somewhere between a few trillion to A QUADRILLION times light speed. Bar none, Flash is THE fastest man alive
Wally West gets one in Flash #50. In the previous issue, he'd been shot by Vandal Savage and left for dead. Now, having run across a desert to face Savage again, and rescue his family, Savage orders his own speedster, Lady Flash, to fight Wally. She refuses. Enraged, Savage pulls a gun and fires at her at point black range. When she is unharmed, both she and Savage are stunned, Savage remarking that she wasn't fast enough to stop the bullets at that range.
Flash: No, but I am. Care to try again? I reloaded the gun for you.
One of Wally West's best moments ever is Flash #54, "Nobody Dies". In the course of an attempted midair hijacking, the plane gets breached and a flight attendant is sucked out, falling to her doom at 30,000 feet. Wally—who can't fly—hesitates...and then jumps out of the plane after her. Because nobody dies, dammit.
In The Return of Barry Allen, Mark Waid managed - well, for 15 years or so - to make people forget about Barry Allen, first hero of the silver age, and convincingly elevated Wally West into position as The Flash. How did he do it? By making Wally stare down his worst nightmare, yet come back and win, culminating with the famous "AND YOU'RE NO BARRY ALLEN!" line. Then again, Waid's first run was basically a series of these type of moments, but this one also served as the symbolic establishment of DC's "Third Generation" of heroes.
The moment leading up to this deserves special mention, as well. Prior to this, Professor Zoom effortlessly curb-stomped Wally, Jay Garrick, Max Mercury andHal Jordan, while loudly declaring that HE was the fastest man alive. Now, he's running well ahead of Wally, confident in himself, with Wally rushing to catch up. Then we get this inner monologue, which is the sign that Wally's finally overcome his complex about replacing Barry Allen as the Flash and is about to even the odds on the battle:
Wally: Max was right. He was right all along. I am afraid. I'm afraid of replacing Barry Allen. (close-up of his face as he picks up speed) But I'm more afraid... OF LETTING THIS BASTARD DO IT!(slams Zoom in the back of the head; cue Zoom's Oh Crap reaction)
Another of the many moments from his run was the resolution of the Terminal Velocity storyline (issues 94-100). Not only does Wally exceed his top speed to save Linda and merges with the Speed Force (their afterlife, so effectively dying), but he manages to return from the other side soon after with a slew of new powers and kicks Cobra's ass and saves the day.
In issue 141, the Black Flash has come for a powerless Wally. After some distraction by the other speedsters, Wally manages to overcome his handicap and get his speed back, then defeats the personification of death for speedsters by running to the end of time where death no longer has any meaning. He then makes a quick stop to the Speed Force to rescue Linda, who had been "killed" a few issues earlier, and returns to the present. BAD ASS.
In Impulse #3, Bart has his first day of school in Alabama, and manages to infuriate every bully and jock he meets, culminating in him leading almost the entire school onto the football field after class. He then lets a full-scale riot break out, and walks away smiling. Also a Crowning Moment of Funny.
Later, when Bart returns in Legion of Three Worlds, Superboy-Prime is absolutely horrified.
During Rebirth, Barry flees from the presence of others, worried his malfunctioning powers might harm them. Superman gives chase, saying Barry can't outrun him — all those races they did showed Barry was only a little faster at most. Barry reminds Clark those races were for charity, and instantly leaves Superman trailing in his wake.
This far and no one mentions Wally's Infinite Mass Punch? When Wally realizes Zoom is not connected to the Speed Force, he simply accelerates to pass Zoom and then goes around the world again just to punch him. The kicker? Wally's going at speeds fast enough to hit another speedster one thousand times before he can blink. Wally only uses ONE PUNCH, and sends Zoom flying from Mount Rushmore to Africa at escape velocity.