Okay. I don't know how good that is, but a lot of the things I would normally recommend, assuming Japanese proficiency good enough to play anything on the system, are text-heavy, so cool obscure things like The Conveni are probably not going to work. Saturn also has the best version of Tokimeki Memorial, too.
That said, TokiMemo has a cool puzzle game, Tokimeki Memorial Taisen Puzzledama, which is absolutely worth checking out. It's not quite arcade perfect because they changed some stuff for the home conversions, but it's an excellent game and better than the PS1 version. Mikado has weekly tournaments for the arcade version because it's so good. Stay away if you don't like hard games, though; if you thought Tatsujin Ou was difficult, the AI of MemoDama's normal difficulty makes Tatsujin Ou look like an entry level game in comparison. I highly recommend it for both arcade puzzle game-loving humans and masochists of any species.
Unfortunately I have some games to anti-recommend: first up is the Japanese version of Powerslave or whatever it's called in Europe, which is 1999 in Japan, lacks the glorious voice of Michael Dorn. This version of the game is perfectly fine otherwise, but if you want your Dorn (and who doesn't?), you'll have to go with some other version instead. The new PC version from last year or whenever isn't quite the same as the Saturn version, I guess, but I've only ever played the Japanese Saturn version.
Also worth skipping is Kaitei Daisensou. This game is super badass, as you'd expect from Irem, but I've heard that the Saturn version sometimes just doesn't boot. Don't risk it, especially when ACA has you covered for this game.
What Saturn do you have? Depending on the motherboard revision, earlier prints of Space Harrier and Out Run will not work. Pretty sure it's not a grey Saturn vs. later versions thing as many would have you believe, it's the actual motherboard, as I believe the earliest motherboard revision white Saturns might be okay, but without some actual research, don't risk it. There are fixed versions of the discs that work on all Saturns. You can identify them by the codes on the discs. I think I have the codes somewhere, so I'll go try to find them when I can. Until then, skip these.
I'd also skip Darius, Layer Section, Garegga, and Batsugun, not because they are bad on Saturn, but because M2 ShotTriggers and Bitwave are the ways to go with all of these. I'd probably say the same about most things that are on ACA.
For recommendations, here you go:
Soukyuugurentai is the best STG on Saturn that actually works (sorry, Kaitei Daisensou, you are the best but you are unreliable!) and you need it! Fortunately, it's also somehow one of the cheapest! You can get a complete copy for about 6000 yen, and you should! Toyama-san told me the ST-V version is bugged and that the unspecified bug was fixed on Saturn, and that the Saturn version is the only version that should be played. I wasn't sure about this for a while, but I recently did some research and found that there are actually 3 versions of the game on Saturn. Most people who know about it know that there is the original and Otokuyou, but there is also a (probably obscure) revision of the original non-Otokuyou version. What's the difference? Well... I don't know lol. Hopefully someone can figure it out.
MemoDama, as mentioned above. Hanagumi Taisen Columns is also really good, and it plays differently enough from its moderately more complex Dreamcast-exclusive sequel to warrant having and playing both of them. It's also only like 500 yen complete.
I know Japanese isn't really practical, but if it is possible, Princess Crown.
After Burner II. This is the best home version of the game, partially because of the Mission Stick. Get the Mission Stick and play this and Space Harrier. This is the best you will get for this awesome game outside of being fortunate enough to find the deluxe cabinet, which you won't.
Saturn also has the best versions of Thunder Force IV and V. No, the Switch version of IV is not better, although it does remove one of the two infinite point milking spots that I am aware of. Scoring is messed up on Saturn, but Saturn benefits from higher audio quality and no slowdown or sprite flicker at all, ever. Even the scoring doesn't really matter much in the end because Switch still has an infinite milking spot.
DecAthlete is also a must-have. Great arcade sports game and it runs in the Saturn's interlaced mode and it looks super sharp, but make sure you have a deinterlacer if you are not using a CRT.
Cotton 2 and Boomerang are different games, but try them both. Boomerang is ridiculously expensive.
Kyuukyoku Tiger II is... uh, yeah. If this game didn't have the Kyuukyoku Tiger title, nobody would remember it even exists, but it has an exclusive Saturn mode. Check it out on Saturn if you can rotate your screen. Skip it and play the arcade version however you see fit if you can't.
Panzer Dragoon and Zwei are required. If you have a Saturn, you need both of them, but if you can only have one, get Zwei. Panzer Dragoon plays moderately better than its remake, too! Hopefully Zwei's remake's development hell will result in a better game this time.
Sonic Jam is one of the best ways to play Sonic 1-3&K. As far as I know, aside from the 90s PC versions, this is the only rerelease of these games that is a port and not emulated, or remakes in the case of Sonic Origins. There are some audio differences, so if you like that sort of thing this is worth checking out. Sonic 2 has an odd amount of additional slowdown compared to the MD version for whatever reason, but they otherwise generally run much better than the MD versions.
The Asuka 120% on Saturn is the last one made by the original dev team. It's really simple compared to what it inspired (the ridiculously complex Arcana Heart) and in Japan everyone prefers the black dot revision of the PS1 Asuka 120%, but it might be worth checking out.
For stuff you probably will have difficulty with without Japanese other than Princess Crown and Tokimeki Memorial, there is Snatcher, Policenauts, Langrisser Dramatic Edition, Langrisser III, IV, and V. Skip Sakura Taisen and Sakura Taisen 2 and play them on PC or Dreamcast instead, as those are the best versions, and the Saturn versions' use of the 320x240 resolution makes the Japanese text harder to read than on Dreamcast or PC.
Dracula X is questionable. I don't like the game to begin with because it's unbelievably boring no matter where you play it, but if I am going to suffer through playing it (and drop it immediately once I get to the inverted castle), I will almost always play the Saturn version because it's the most complete. The loading times are greatly exaggerated, but the slowdown is not. It runs SUPER TERRIBLY at times and for no good reason as far as I can tell. Get it if you want it, I guess.
There's probably some more stuff. I'll probably remember something important later.