The finale of The Return of Barry Allen: Faced with the prospect of Professor Zoom killing and replacing Barry, Wally throws off 10+ years of psychosomatic blocks on his top speed and decks Zoom. The look on Zoom's face alone makes it worthwhile, as does Wally's shout of "You're no Barry Allen!"
The moment leading up to this deserves special mention, as well. Prior to this, Professor Zoom effortlessly curb-stomped Wally, Jay Garrick, Johnny Quick, 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 in the battle:
Wally: Max was right. He was right all along. I am afraid. I'm afraid of replacing Barry. (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)
Never has a No-Holds-Barred Beatdown look so satisfying. Then remember that that is Professor Zoom who was on the recieving end. During his "The Reason You Suck" Speech at the bastard, Wally admits that he was very tempted to kill him right then and there for all the crap Zoom has pulled (or is going to pull), but chooses to use the Cosmic Treadmill to Ret-Gone Thawne instead. Now extremely frightened, Thawne tries to chase after Wally using the Treadmill, but instead gets sent back to his own time. Wally reappears somewhere else in the present, never having used the device in the first place. Not only has he overpowered Thawne, but Wally completely outsmarted him as well.
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.
A villainous example: Zoom II is so "fast" that the combined speed of four of the earth's greatest speedsters (Wally, Jay, Bart, and Jesse) need to be combined into one body in order to get close to catching up with him.
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.
In issue #49, Wally had been shot by Vandal Savage and left for dead. Now, having run across a desert to face Savage again, and rescue his friends and family, Savage orders his own speedster, Lady Flash, to fight Wally. She refuses. Enraged, Savage pulls a gun and fires at her at point blank 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? (Wally makes Savage aim the gun point-blank at Wally's head) 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 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.
This is actually considerably bigger, because at the end he seems to outrun the Big Bang on his way back to the present (which it's heavily implied he did offscreen in the last arc, "The Human Race", as well). During the Big Bang's 'inflationary epoch' (lasting about 0.000000000000000000000000000000000099 seconds), it expanded from a single point to about 10^30 times bigger than the observable universe. An expansion which Wally outran. This would mean going somewhere in the range of over 32.77 sexvigintillion times the speed of light. In one Planck time (the smallest scale of time in which quantum gravitational effects are still likely to be important), a period in which a beam of light could cross 1/10000000000000000000000000 of a hydrogen atom, he could run from one end of the observable universe to the other and back over 2 sextillion times. And that clearly isn't him going anything like flat-out, because he wasn't at risk of vanishing back into the Speed Force. As Jay Garrick rather understatedly put it in Final Crisis:
Jay Garrick: It's a little-known fact that death can't travel faster than the speed of light. But Wally can.
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 Funny Moment.
This really needs to be emphasized. Bart didn't just beat Prime he handed the villain his very first loss and did it completely on his own. Later efforts at dealing with Prime consisted of two Supermen flying Prime through a red sun to depower him and he still managed to kill one of them before going down, the Guardians of the Universe assigned several of their Lanterns to making sure that Prime would stay locked up, and the Titans eventually had to throw him into the Source Wall that even Darkseid couldn't escape on his own because literally nothing else could stop him. Bart meanwhile not only defeated Prime on his own but said defeat left Prime terrified of Bart specifically and moderately phobic of speedsters in general.
Later, when Bart returns in Legion of Three Worlds, Superboy-Prime is absolutely horrified.
Wally's Infinite Mass Punch over in JLA. When Wally realizes Zum is not connected to the Speed Force, he simply accelerates to pass Zum 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 Zum flying from Mount Rushmore to Africa at escape velocity◊.
Flash #217 (Vol. 2) (an Identity Crisis tie-in): Batman shows up at Wally's job to confront him over Captain Boomerang's murder of Jack Drake (Tim Drake's father). As Batman finishes up his "handle your rogues or I will" intimidation routine, Wally changes into his Flash costume - while Batman still has his hand on him - and says "Are you finished?"
Flash: I want you to know. You touched me because I let you touch me.
He then proceeds to go in on Batman for assuming that just because his Rogues had goofy names and costumes and weren't insane murderers, that they were easy marks. And throws in an Armor-Piercing Question for good measure.
Batman: He lost his father, Wally. To Captain Boomerang.
Flash: In your head, it should've been The Joker or Two-Face that killed Jack Drake. Is that it? Would that be more acceptable to you?
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.
The speed of Wally and Barry in Issue 49. Superman tries to chase after them, but they leave him in the dust with Superman having to literally catch his breath. In addition, their acceleration is so fast that it disrupts the Microverse, antagonizes Zatannas magic and Swamp ThingsGreen, plays havoc with the fabric of the multiverse, and breaks the Speed Force.
Wally gets a double Moment of Awesome. While Barrys acceleration played a huge part, Wallys is the one that actually did all those things.
In the following issue, as the two Flashes try to catch Zoom, who, as always, is faster than the both of them. However, Barry has some encouraging words for Wally, who manages to catch up to Zoom and defeat him, proving himself the Fastest Man Alive.
Wally: How are we even going to catch up to Hunter?! I'm running as fast as I can and I'm barely keeping up with him!
Barry: You asked me if I remembered the first time we raced, but I never answered answered you. Of course I remember, Wally. I know I've forgotten a lot of things, but...how could I ever forget that? I was always so lost in the science of the Speed Force that I'd miss out on having fun and just cutting loose. But you always knew how to enjoy the speed...and the day we raced. That was how you won. And now you need to remember...you're Wally West...and you're the fastest man alive!
Flash #750, and specifically the third story, which features Jay Garrick in his own story in a Flash title for the first time in years. And it's Jay in his prime.
Finish Line: When the Flash family is about to be overwhelmed by the Legion of Zoom, Max sends out a telepathic distress call through the Speed Force. Who answers the call? The Flash family throughout the ages (even including Krakkl and Dark Flash), Fuerza, Steadfast, Wally's twins Irey and Jai, and the Renegades. What a reunion!
Also from Finish Line is issue #761 which reveals that through a mixture of Time Travel and using Negative Speed Force frequencies to act as The Corrupter Thawne has managed to orchestrate nearly every trouble that not just Barry but every member of the Flash Family has faced since Rebirth began. Godspeed, Flash War, Heroes in Crisis, Thawne nudged everything in place to make it happen. The Reverse-Flash once said he was every bad day that Barry ever had and he well makes good on that boast here.