This was one of the arcade-specific experiences that I've never quite had at any other point in my life. MMORPGS and forums have given me some of the feeling of being at an arcade, but this was something unique.
I was perhaps too young, or for whatever reason not good enough to be noteworthy at the arcades. But (as mentioned elsewhere in this thread), my best friend was. He was notoriously good.
We'd go from arcade to arcade in town, until they'd ban him or (in one case) up the difficulty just to get him to leave.
We'd play co-op games where he carried me through and it was a kind of bonding experience I can't quite compare to anything else.
He was so good at the competitive games (in particular SF2) that people wouldn't challenge him. Why waste a coin? I sometimes put in a coin just to bait others, because the clever players knew that if you saw someone playing SF2 alone for a while, they were probably really good. He'd give me 10 cents to reimburse me :).
Whenever a new arcade opened up (usually in a shipping container, but sometimes 'real fancy'), we'd rush there and first try the new games, but then get back to SF2 and hope there were players that didn't know about him yet. It usually worked for a while.
But possibly one of the most vivid memories of my childhood was the time that, while I was faffing about on other arcades, out of the corner of my eye I'd see some other guy (it was mostly men, but perhaps that's partly culturally. women became mothers-in-training in their teens) walk up to his solo SF2 play, and pop in a coin.
I swear, when that happened, it sometimes felt like a Western. I'd notice first, on account of keeping an eye on my bestie, but others 'in the know' would nudge each other and cut off whatever game they were playing to watch the spectacle.
A crowd would form around my friend and this 'new guy', and, of course, most of the time he'd do the equivalent of drawing so quick that the other guy didn't stand a chance. Sometimes he'd play around. Pick one of the weaker characters (that monster one I don't remember). Or humiliate his new adversary by offering to play with one hand.
I think there was only one time where he struggled, and it turned out this guy was a dude from the capitol and was known there for being the local SF2 champion.
EDIT: Oh, and just to add some color to this story in case anyone liked it: I was one of the few people in town with a personal computer. My parents told me to not mention it to my friends for fear of theft. I told this friend and I will never forget the experience of having him over and playing games together. This was a 486 and we played Wacky Wheels and (I think) Doom and One Must Fall, the latter which was closest to the fighting games he was so good at (or perhaps a similar game?).
These games were clearly a step down from what we got to play at the arcades, but the fact that we could play them without having to put in coins (even if they had the 'continue' and 'credits' screens) was just mind-blowing to the both of us.
Sadly as I moved on to RPG's and RTS', he stuck with the arcades and we drifted apart in this regard. We bonded over watching badly dubbed films though, The Matrix being probably our favorite.