It depends if it's in an actual arcade or just arcade games as a whole.
I've been using MAME since its initial release in the late 90s.
I also love numerous music games, but I'll talk about them more properly in a different question.

My most commonly played games in real arcade settings were DDR 3rd Mix Korean V2 (at a skating rink I frequented), DDRMAX2 (at a proper arcade many years later), DDREXTREME (they upgraded it), Soulcalibur II (at that same arcade), Raiden II (I got really good at it, now I can't play it worth squat though), Mocap Boxing (although I wore out my arms every time!). I also, as a little girl, took trips to a science museum where they had a Virtuality 2000SU machine with games like Zone Hunter and I enjoyed that greatly at the time. Can't even emulate that stuff today, what a world...

Through emulation, the one I fell most in love with is Salamander 2. I was following blog posts about MAME work to get games working, break their decryption, dump them, etc. And when Konami GX emulation finally came into being, I tried every dumped Konami GX game. I loved the Tokimeki Memorial puzzle game, stuff like Parodius was great... but I really, really clicked with Salamander 2 and it remains my favorite horizontal shmup to this very day.

I've talked in a previous answer about my love for Numan Athletics, and I do absolutely adore that game. It's so funny, so challenging, and makes a great game to just sit down with a friend or two and play any time. The sequel Mach Breakers is... all right, but it's missing a certain I-don't-know-what.

Broadly, through MAME I was willing to try just about anything. I found many fighting games I enjoyed, and got into King of Fighters despite only being exposed to Street Fighter for much of my life. My favorites are 98 and 2000.

I also very much love Twinkle Star Sprites and Magical Drop III.

My favorite Metal Slug game is Metal Slug 3, but in actual arcade settings I mastered Metal Slug 2 for a time. The sheer amount of lag made it an exceedingly easy game to 1CC, probably more than any other in the series. Can't blame them for making Metal Slug X, the game really deserved a better re-release and it's good that it got one... even if it's a shame you can't play it in any sort of "original mode" without the other changes X made.

My favorite vertical shmup is ESPRa.De. I've never had the pleasure of playing on a real cabinet, but I've been emulating it on MAME for ages and I own the console port ESPRa.De. Psi which is very good.

I've played Rampage World Tour on a real cabinet with other people numerous times when I was younger, though I now consider it to not be that fun of a game past the first 10 minutes or so, unless you've got a group that's really funny and talkative. But then, what game isn't great with a group like that?

My favorite Capcom fighting games are Capcom vs SNK 2 and Street Fighter Alpha 3. My favorite outside of Capcom and SNK proper is Rage of the Dragons. I've never played any of these on real cabinets, but I invested a lot of time in Marvel vs Capcom 2 at an arcade when it was new. It was really something being there at the time, having absolutely no idea what new characters would appear after enough play. It wasn't something everyone knew in advance, so you found out in a similar time frame to when anyone else did, and it was a surprise every time.

I was the local ace at Initial D Arcade Stage ver.2. I regularly stacked many wins in a row, which would give your car an "aura" that got bigger and more intimidating the more wins you would get. I had a rainbow aura on my car a few times. I unfortunately would get very upset if I lost however precisely due to the fact it meant I'd lose my aura...

In Soulcalibur 2, I was never all that great, but Conquest Mode was a big thing at the arcade I was a regular to. The most outstanding player was a guy called "DanTheMan". It seemed like no one knew exactly who he was, but he was a really powerful Nightmare player. I eventually entered a tournament at the arcade with one of my friends, and DanTheMan was also an entrant. He, of course, wiped the floor with all of us, but we were just happy to get even a single win before facing him. Mythological tier stuff.

The arcade had a Cyber Sled machine for a few weeks and I became briefly very enamored with that game due to the general presentation of the game and its cabinet.

I finished Gauntlet Legends on a real cabinet once. Not a lot to say about it but clearly I enjoyed it if I kept going at it until I got through it like that. It was the original release, not Dark Legacy.

There was also a period where I had a lot of hours on Mortal Kombat 3 at an arcade, and was considered one of the better Sub Zero players. I don't really like Mortal Kombat that much anymore. Well, I like the lore and characters, but the gameplay, I really dunno...

This is starting to come off as just a huge list of various games I ever played, so I think I'll draw my response to a close. But I was a huge mall rat and arcades were one of my favorite things ever. I really miss that experience a lot.

I don't even think the games themselves are as important as the overall vibe and experience, and we as a culture have lost the narrative on that one, replacing arcades with Dave & Busters type experiences designed to only keep your attention for a few moments, which I'm sure is more profitable, but an entire kind of community is basically gone unless you live directly around one of the remaining real arcades out there.

I like it a great deal. Shame to hear about all of the issues with Kiwami 3.
My favorite is Yakuza 4. I started a stream playthrough of it, but it got sidetracked by other things.
It will return to my streams rather very soon.

It resembles my daily life a great amount, including the parts about helping others I don't necessarily really understand but totally vibe with, and the parts about having really screwed-up experiences with UFO catchers.

Akiyama is easily my favorite character. It's necessary to understand his more infamous quotes in larger context instead of taking them out of context like people have sometimes done to hate on him.

Honestly I think they're all equally wonderful, but some may be less accessible than others.
For instance, while I love Mermaid Melody very deeply, I think it's a big undertaking to watch because it's nearly 100 episodes long despite being a fairly vapid show made for particularly young children.
It's also hard to recommend any show that only has very low-quality fansubs and no official subs, for example, Powerpuff Girls Z. Good show, but the only subs out there are TV-Nihon, and the official version is just a rewrite dub-only thing...

I would recommend Cardcaptor Sakura to absolutely anyone, very openly. It IS as good as they say and every aspect of it is largely great. (I just don't like the main canon ship...)

There are a lot of shows that try to deconstruct Magical Girl shows as a genre and do so poorly, or that satirize specific things about them in ways that show they've never actually watched or read a Magical Girl work. I would avoid stuff like that, and there's a surprising amount of it out there.

The only deconstruction I'd recommend is Madoka, and it's definitely in the "watch this after you've seen some other Magical Girl shows first to understand the genre and get the most out of it" category of things.

I can't recommend the sidestory to Madoka, Magia Record. They did not know what they were doing when they tried to make an anime out of that game. It's a good story at base, but the anime is a confused mess. Only watch it if you really want more Madoka.

Magic Knight Rayearth is a classic that sits on a line between isekai, magical girl, and mecha. It's very strongly worth a watch, as long as you watch the series. The OVA is a very strange inversion that doesn't work well. It has redeeming elements but should be avoided. But the series? A must-watch.

One of the strangest adjacent things I ever watched was a show called Ultimate Girls. It's like Ultraman if it were an ecchi show where girls transform into giant girls and their clothes melt off. Cannot recommend, although the music, specifically, is good. Amuro Ray's original voice actor plays the perverted mentor character. As a result of the transformation sequences and such it is Magical Girl adjacent, but what even is this show? How did it get greenlit? Avoid at all costs.

Avoid Naria Girls. It feels more like a confused parody skit than anything else and it makes me cringe if I am being completely honest with you -- something that VERY few shows do. Like, period.

If you want the classic recommendation, all versions of Sailor Moon are good. Yes, even the live action one, it's just very different. They are all different beasts. Try them all. See which one you like most. Sailor Moon is what got me into the genre, as is true for many people. Remains an easy recommendation.

Seriously, no matter how many things I watch of the type, I feel like Cardcaptor Sakura is always going to be the absolute top recommendation. It's the Magical Girl show. Best in class. Even with so many things being made over all these years, I'm not sure anything will ever truly outdo it.

But my understanding -- advice I have long avoided despite my love for Magical Girls -- is that you should also check out the PreCure shows because there's something there for everyone. Maybe I'll watch them someday instead of only watching literally everything else.