CrossCode. It's an SNES-style action RPG with very fun combat, 2D-Zelda-like puzzles, and a genuinely charming well-written story that was made in HTML5 and JavaScript for some reason. It is genuinely my favorite game of all time. I habitually proselyte this game to friends, but check it out for the love of God

Awesomenauts. The coolest 2D platforming MOBA. The gameplay is super fun and has a surprising amount of depth. Unfortunetly the devs have almost abandoned it and the playerbase is small (still active tho) but it's still one of my favorite games ever.

Just for your information, there are actually two other games related to Rocket Slime. Unfortunately they are JP only. The one that release outside of Japan is the 2nd game. There's a GBA game that came out before it and a sequel to the DS game focused on pirate ships

I really loved rocket slime as well. There's a spiritual successor called connectank on steam that gives me the same vibes, and has fun co-op!

Micro machines was beautiful. The closest I've got to reliving the pure mayhem was probably Mashed (I think) for Xbox.

Alter Ego, a 1986 DOS game that's still one of the best life-sim type games ever made. You start out as a baby and work your way through life by making choices. They can lead to a wide variety of outcomes, including dying tragically as a child, etc... You can play it free online or they've made updated versions.

Digital Devil Saga on PS2. It's a favorite, easily outshines other SMT games in narrative, character development, and plot twists.

Yet I bring it up at a wedding reception and I'm the weirdo. Pfft.

Iji, a free indie platformer shooter, almost like a 2D immersive sim about a girl who trying to fight off an alien invasion using alien tech that got implanted on her. It's very cool! And it's free free, not freemium microtransaction nonsense.

People bring up Journey a lot but another game by that same company called Flower. It's a short, simple game that I will never forget, a beautiful masterpiece.

For me it's gotta be Secret of Evermore for the SNES. Kinda old game but I absolutely loved the gameplay and story when I first played it as a kid. Have been replaying the game many times and it's always a great experience.

The journeyman project series (1, 2 and 3) had a major impact on my childhood

Golden Sun. They were the best RPG games I've ever played and never get the love they deserve. Don't know why, I've never played a game that struck me like those 2 games did.

The first few Advance Wars games too, Advance Wars and Golden Sun were a huge part of my childhood.

Ogre Battle 64 is mine. The n64 wasn't exactly known for rpgs but this had so many characters, a ton of depth and an intense story that I wish it was brought up more. This was my intro to a tactical rpgs and I felt like I went right into the deep end.

I humbly submit for your approval Yuppie Psycho, a fantastic Steam horror adventure about a kid's first day in a truly nightmarish company. It's got a unique style, and genuinely unnerved me in places. Really creative work, and it deserves so much more attention.

Anyone remember "War of the Monsters" on the PS2? Such a fun monster mash single-screen multiplayer game.

Let's see what I can come up with (and see if I can remember the names correctly!):

• NES: Back in the day, it was probably River City Ransom. Growing up, it was a game my brother and I loved to play... but no one ever knew what we were talking about at the time. Now the Kunio games are a bit more known, and with River City Girls 1/2 they're getting attention, which is great.
• Gameboy: Avenging Spirits. When I was younger, a friend and I loaned each other a bunch of our games. Sadly, he ended up moving away before we managed to swap back, and he got the better end of the deal when it came to the games. However, I did get left with a copy of Avenging Spirits... the game is a bit strange but its very fun and the sprite work is just adorable.
• SNES: Dragon View. It has great sprite work and a very (at the time) cool looking 3D overworld you can stumble around in... Solid gameplay and some RPG elements make it a nice little gem of a game.
• GBA: River City Ransom EX. Same deal as the NES version. I worked at Toys R Us around this time, and I think I'm the only person who purchased this game from the store...
• PS1: Brave Fencer Musashi. Someone else already mentioned Einhander, so I'll go with my other go-to PS1 gem from Squaresoft.
• Saturn: Guardian Heroes. While I bought the console for X-men vs Street Fighter, I go it with a handful of games on the cheap at EB Games: Magic Knight Rayearth, some crappy 2D Dragon Ball Z game, X-men vs Street Fighter (and a 4in1 cart of course!) and Guardian Heroes. Its such a well made beat-em-up that really doesn't get a lot of love because most folks never played any Saturn games.
• PS2: Way of the Samurai. Maybe not super unknown, but definitely a niche game back when it released in the US I think.
• Dreamcast: Cannon Spike. I bought my DC for Capcom games (and SoulCalibur), and this is one of the many gems on that console that never really pops up in discussions. I bought it on the sole merit that Charlie/Nash was in it, but it was wacky and engaging enough to warrant a place in my heart.
• XB360: Tenchu Z. I loved Tenchu back on the PS1/PS2, but this was probably the one that most folks didn't touch... it was a bit weird but a friend and I played the hell out of it on many a weekend back in the day.

Any other console I either didn't own (Genesis, Gamegear, PS3, etc) or just couldn't think of anything that really stood out as a hidden gem (PSP, PSV) or are more current and also don't really have anything that ranks (PS4, PS5).

My favourite games are NoX, Morrowind and Populous the beginning. Only Morrowind is still really talked about, sadly.

Full Spectrum Warrior.

A real time, over-the-shoulder, squad management tactical game.

Imagine Brothers In Arms style tactical command and contextual actions from AI squad members, mixed with a modern setting, mixed with pulling the player out of actually doing any shooting and putting them entirely in the role of command, and give it high lethality and a requirement to save all friendly wounded AI squad members (wounded ones have to be carried back to a medical tent).

Really unique couple of games that nobody has iterated on.

Snowboard Kids 2 for the N64. One of my top 3 favorite Mario Karts.