There are some YouTube videos that mention it - search “Galaga Glitch.” The quick version: if, on level 1, you can shoot all of the aliens except for the two bees that start in the far left of the front two rows, then avoid them long enough without shooting them, not only will they stop shooting, but none of aliens from that point on will shoot. One of the videos says that it happens on all Galagas, but I thought there was at least one ROM version that fixed it.
Pinball better count!
I was never any good at video games, but I am great at pinball, and in particular, a 1978 Bally early solid state (electro-mechanical) game called Lost World. It’s difficult to explain to someone who did not grow up with just “bells and pop-up target” mechanical machines how unbelievably cool a machine like Lost World was in the late 70s.
I could play a quarter until I had to leave. It was also unbelievably cool to be a 12-yr-old girl, and give games to a younger kid when I left. Usually it was guys in their 20s who did that. A few times, I gave games to high school guys, because there was no one younger than me at the arcade.
Once, some older boys were playing the machine when I got there, and I asked if they’d let me know when they were done. They told me I had to win the game from them-- and I did. By almost doubling the score of one of them, and still way outscoring the other.
20 years ago, I found one fully restored for sale for $400, and snapped it up. Still have it. I’ve turned it over several times. It’s still my favorite machine. I own a collection of pins, including some that are objectively cooler than Lost World, but I still love this one the most.
I was pretty good with Street Fighter II back in the day (the original vanilla one). I got pretty good at playing Ryu in the arcade with the stick. I wasn’t unbeatable but won more than I lost.
If there was any game that I ever dominated people with, though, it was Goldeneye for the Nintendo 64. Not an arcade game, but I had a group of friends that would love to play 4 player split screen. I played the game enough that I learned all of the levels inside and out, including the secret passages. I got so good that I would play 3-on-1 and just toy with them, sometimes even tricking them into shooting each other. Eventually I was banned from playing the game with them, which to me is the best compliment ever.
I think that’s the only video game I ever completely crushed everyone at. And since it was almost 25 years ago that I was that good I’m pretty sure I’d suck at it today.
I couldn’t last forever on a quarter in Q*Bert, but I could beat most people because no one else really liked it as much as I did.
I knew a bunch Q*bert Masters; the timing in that was insanely dodgy IMO so people who mastered it always fascinated me.
Zaxxon was another game with dodgy timing; I was okay but my friend Joe could play all night for a quarter.
It was great when we discovered we were about equally good at Xevious, tho. We’d tie that machine up for hours sometimes.
If you count two-player games - I would play “Pong” (or a similar clone - hitting a “ball” back and forth) with a friend, and we both became so good that we would play to “first point wins” (the game normally ended when a player reached 11 or 15 points - depending on the machine). This usually took us about 45 minutes before someone “scored” - we would then pass the machine off to other players, who would be finished within a couple of minutes.
That was an excellent one. I can’t claim any great prowess on it but I did okay. It was always fun to get it to say “The Mamoushka!”
My top game was a scrolling shooter called “Heavy Barrel”. It had a joystick for character movement, a knob to point the gun (which only fired at eight-points (45-degree increments) around the circle) and then the buttons for shooting and grenades. Used to make it through to the end, sometimes in one go, sometimes with an extra quarter. The end boss fight had terrifying audio, with the boss bellowing “YOU DIE! YOU DIE! YOU DIE!” constantly.
I also used to rule at Battlezone (the old wireframe tank battle game) but it gets a bit dull after a while.
Never played in a tournament, just used the game to pass time in college (I was true to my sweetheart).
Still have a callus on my left thumb from the joystick.
Challenge for me was scoring as close to the 1 Million-point mark without going over, so you could put your initials in the top score list. Go over a mill, the points reset. Turns out one needed to hyperspace repeatedly to destroy the new ships you got when you passed a certain point total.
The campus rec center had about a dozen video arcade games. I remember one I achieved a fair degree of proficiency with was Elevator Action. It wasn’t a hugely popular game, so perhaps me getting the occasional high score wasn’t that great of an accomplishment.
In terms of pinball games my favorite was Pinbot
I remember playing that, with those slow-ass bullets. 
I once got a high score on that game, beating the previous high score by some ridiculous amount. IIRC, my high was two places to the left of the previous.
There was a sequel called Race Drivin’ that let you choose from a few different tracks and cars. On the simplest track, I could race it to a break-even point. That is, for finishing a lap you’d get 30 seconds added to the timer, and I could do a lap in 29-something seconds. Eventually, I’d make a mistake and lose enough time that the game would end, but I think I got 10-15 laps a few times.
An arcade I went to the in mid-90s had a tournament while I was there on the Daytona USA game. I was good at it, but not great. But I was observant enough to spot some details in the game that I could use to my advantage. I wound up winning the tournament; got a t-shirt.
I got to the last level of Marble Madness a few times, but never completed it. A friend of mine could finish Marble Madness and Major Havoc.
For me, it was Gottlieb’s “Card Whiz” (2 player) a.k.a. “Royal Flush” (4 player):
It’s another electro-mechanical pinball, this one from 1976. It was asymmetrical, which Gottlieb liked to do from time to time, and it was challenging. But it was my favourite, and I played it a lot, and I got quite good at it, to the point where I could play for hours on a single quarter.
That was a very good game. I wasn’t as in love with it as with Lost World, but when I lived downtown in my college town, there was an arcade in walking distance-- the last arcade, that wasn’t “retro”-- this was right around 1990-- and Pinbot was my best game there. It was the last place besides The Pinball Hall of Fame where I ever saw a wall of pinball machines.
Man, was that fun, The Pinball Hall of Fame. I’d inherited some money, so I went to Las Vegas for a couple of days, saw Penn & Teller from a fifth row seat, and the next day, played pinball for four hours-- would have been longer, but my wrists were getting sore, and I’d already beat carpal tunnel syndrome once. My wrists were sore for about five days, and I got a little worried, but I was taking naproxen every 12 hours, and it cleared up.
They had Royal Flush at the pool place in town. When I’d go there with friends, I’d insist on playing. They’d all roll their eyes. I was the 90s, and they didn’t even quite get new releases-- why I wanted to play a bells-and-springs pinball machine was beyond them.
I don’t even understand how to get better at it. It just seems inscrutable to me. Spin, shoot, blaster, die, repeat.
I was actually thinking of starting a thread to have someone explain to me how to play it.
And I own one!
Tempest is great once you fully grok the planes.
And to get it to flip the flippers twice in time to the theme, during start.
Totally agree. I’ve been there also, a few times, and each time is a trip down memory lane. There are the games I grew up playing, and it is great to play them once again. Many machines have an info card telling you when the machine was made, and other interesting facts about it. And it is so nice to see a wall of pinballs, just like were in the downtown arcade I frequented when I was younger.
I know what you mean about spending four hours there–I’ve done the same. It doesn’t seem like it, but when I check my watch after playing a number of games, a few hours have passed. It’s true: time flies when you’re having fun.
We called the electro-mechanicals, “clunkers and bangers.” 
Black Knight was a pinball game that seemed to be everywhere in the 80’s but I never came across anyone who was really good at it or claimed it as ‘their table’. I remember hearing about how they had to reinforce the sound of the ‘s’ in the game’s tag line “I will Slay you”. Might be easily misheard in a noisy arcade, after all.