Red Dead 2, played it like 5 years, or maybe 6 years, after it released and i didnt like it at all. It really bored me, and im surprised the narrative of the game is so praised cause while its certainly well fleshed out, i dont think its particularly interesting or original. I dont know, it didnt do it for me, this game felt like a slow burner that never really takes off for me.

On the opposite side of the spectrum theres Bioshock, which i also played like 8 or more years after it released? got it when the collection came out. And boy did i love it.
Stardew Valley as well. Played it for the first time this very year and man did i love it. Dunno why i was holding out on it for so long.

There are a lot of games I tried out a lot later due to retro gaming.  Some I had the benefit of playing on a PVM which helps the experience.  (I will indicate which ones.)  Here are some of the more well known ones:

Genesis
Phantasy Star IV - This game is often compared to Final Fantasy VI.  I will say the music on PS 4 is incredible, at least as good as FF6, and I say that believing that Nobou Uematsu is the greatest composer in all of video games.  However, as a whole, I think FF6 is a much better game.  PS 4 is a good solid game overall, but it will never make it into my top 100, unlike FF6.

Shining Force II - I couldn't get into this game when I first tried it.  I did play Shining Force I back in the day and loved it, but I first tried SF2 much much later.  My main hurdle is I wasn't looking for a game with exploration elements in it.  Once I got over that I gave it another chance, and now I love it even more than SF1.  This is the second best turn-based tactical game ever made after FF Tactics.

Streets of Rage I, II, III - These are good, solid beat em ups.  I still like Double Dragon better.  Of the three SoR2 is the best and SoR1 is noticeably weaker than the other 2.

Golden Axe (PVM) - Loved the arcade version back in the day, but first played the Genesis version a few years ago.  This is my favorite Genesis game.  So much fun.  I love coming back to this.

SNES
Super Punch Out - I first played this on the SNES classic.  This game is fantastic and reminds me a lot of arcade Punch-Out which I really loved.  It released a month before DKC, which is why I think a lot of people overlooked it and it also is a different style than the NES game.

Final Fantasy VI - I kind of tried this out when it was current, because I rented it.  I got a little past the Opera House and figured I was close to done, based on how long previous FF games were.  I finally went back to this many, many years later and got to finish this.  There is a reason why some argue that this is the best FF of all time.  I'm glad I finally got to complete it.

Earthbound - Another SNES classic, and I played this after beating Undertale multiple times, which may have affected the experience.  This is a very good game, but I think Undertale is clearly better.  That may not be a fair comparison since Undertale wouldn't exist without Earthbound.

Final Fantasy V - Similar to my Earthbound experience, I played FF5 after FF Tactics.  Tactics is the better game, but the job system in Tactics comes from FF5.  This is clearly a good game, that I would have liked more if I'd played it before FF Tactics.

Playstation
Suikoden 1, 2 (PVM) -  I played these in order.  Gotta say that Suikoden 1 was so much better than I expected.  This game was a real treat and not like any other game I had previously played.  I played Suikoden 2 for about 15ish hours and then quit.  I played these games back to back and by that time I was Suikodened out.  I'll probably have to come back to Suikoden 2 at some point and give it another chance.

Castlevania: SotN (PVM) - My favorite Castlevania is still Super Castlevania IV, but SotN is #2.  I say this still holding that linear side-scrolling Castlevania is the style I prefer over Metroidvania.   Still, SotN is just a damn good game.  Glad I finally got to play it.

XBox 360
Lost Odyssey - Tried this for the first time just a few years ago.  This felt like the Final Fantasy game that I had been missing since FF13 released.  It was a lot of fun, but I kind of lost interest about halfway into the game and still haven't finished it.  I need to go back and finish to see if the gameplay picks up again.

Gameboy Advance
(played these games on S-Video which also makes them look really good)
Astro Boy: The Omega Factor - This is the best action game I've played on the GBA.  It's so much fun and a compelling reason why you want to play GBA games on the big screen.

Castlevania: Harmony of Dissonance - Another great GBA action game.  It has a Metroidvania style, but the character uses a whip which I really appreciate.

Metroid Zero Mission - Great graphics, great controls, great music.  Gameplay?  Sucks!  Overall an inferior experience to original Metroid in spite of the improved production values.

Expedition 33 and Death Stranding 2. The former lived up to the hype and then some. The latter was as weird as weird gets but man... talk about a masterpiece.

Finished both Mass Effect 1 and 2 this year(X360). Old but gold.

As a European, Dragon Quest as a whole, as the first one to come out here was VIII. Similar for Final Fantasy, which I started with X, but never had nearly the same pull to me as Dragon Quest.

And I'm absolutely hooked on the series since I started the demo of that game.

3D Zelda might also count. My first one was Wind Waker, but the stealth section at the start and the control scheme (so wished I could invert the axis) turned me off. Ocarina of Time was better, but still not quite for me. Then came Breath of the Wild, and it changed everything for me...

On the PC side of things, the Wizardry series. It's the last of a series that started over 20 years prior, and I pretty much played them in reverse order after starting playing Wizardry 8 in 2004.

Any Nintendo game released prior to 2017.

I could probably mention most games I play, but instead, I'll mention one. I could do others too, but I don't feel inspired to do so, so the one will have to do.

I recently finished Dark Souls Remastered. It looked aged, but other than that, it was just fine. The controls were a bit janky though, but it didn't necessarily feel like it was at least primarily because of the age of the game. I guess today controls wouldn't necessarily be designed like that anymore, but reasonably, the controls worked well enough most of the time. There's definitely some bad designs in the game though, but it's probably not something that couldn't happen today as well, so it's not really strongly related to the age of the game.

Xenoblade Chronicles. I didn't play it until 2018 on the New 3DS and it became one of my favorite games. I knew of it since it came out on the Wii, but I just didn't bother.

Pokemon Black 2 / White 2. I didn't play these until 2017 even though I played all previous Pokemon games the year they released since Firered/Leafgreen. One of the best Pokemon games with the best content.

Super Mario Odyssey. Didn't play it until 2022 and I don't know why I waited so long since 3D Mario are some of my favorite games and this is now one of them.

Fire Emblem Awakening. Played this before Fates came out in 2016 and I was instantly hooked and is my favorite Fire Emblem game.

Ratchet and Clank 1 - 3. Didn't play Ratchet and Clank until like 2012 and these games were so good. Even though I had a PS2 growing up I never played these and I was missing out.

This year and last I've been catching up on 360/PS3 games I missed and picked up stuff like Ace Combat 6, (loved it) Stranglehold, (loved it) FEAR, (amazing) FEAR 2, (garbage) Remember Me, (rough but interesting) Alpha Protocol, (same) Burnout Revenge, (awesome) and Ratchet and Clank Nexus. (Solid)

Great to know. Both games are next in my list of backlog to playthrough.