The more rare, obscure, or just a guilty pleasure, the better. Maybe you grew up with it, maybe it’s just the nostalgia talking, any reason is fine.
I’m looking for a new game to play, but I’m running out of games to collect!
My favorite is games for original DMG, but you’re welcome to include Color it’ll advance games too!
This is a little off topic for "RetroGaming", but my favorite new soon-to-be-hidden gem for Gameboy Color is "Grimace's Birthday".
https://www.grimacesbirthday.com/
The overall game is only about ten minutes long, but it's just so dang well made for a silly throw-away advertisement, and I just adore that it's a Gameboy Color game released in 2023.
Edit: To be clear, I have no association with anyone involved in the game. It just gives me the giggles to get a new retrogame for a licsned property, for actual classic hardware in 2023.