I'd like people to list games that are so beautiful, that they literally make up the culture that is retro gaming. These games hit all high marks in my book, or at least a mark that if you simply ignored any of these games when you were a kid, load it up on RU, and play it, it's a crime against gaming humanity.
I'm personally going to list mine that I don't believe everyone has played, I don't want to state the obvious that are on other players lists.
(That includes Final Fantasy Series, Donkey Kong Country series, Chrono Trigger, Secret of Mana, Super Metroid, and so on and so on)
SNES
Magical Quest Starring Mickey Mouse: First off, this is in the list because of the beautiful music, not only did someone make this game and care about it, but the creativity and motivation to create a game that has secret paths, secret areas, some of the best music on the snes, and more, it just blows peoples minds. There is apparently a sequel coming with the same style game play that also involves mickey.
Actraiser (1 and 2): Actraiser 1 was a great game because not only did it demand a difficulty that scaled (well) as you progressed, but also taught you life lessons when you were this young. Actraiser 2's difficulty shot up, and required more of a scale of memorization to beat some of it's stages, but it's music was some players first times hearing classical music being revolved around a video game, which blew peoples minds.
Out of This World: Some players first time with an action/adventure sim, it was great in the fact that you learned about the story, your character, you really felt for him, and in the end, it taught you about yourself. It also pushed the SNES to it's limits in regards to what you could do with it.
Sega CD
Sol-Feace: This is "Sol-Deace" on the SNES, but holy god this music just made me go nuts. Go on youtube and watch some gameplay for this plane game. the music was so crisp, so upbeat and crazy, I felt that I was playing a legitimate MAME arcade at my house when I was a kid loading this game up.
Streets of Rage: On this list because I don;'t believe many people played this on the Sega CD, let me tell you not enjoying this game on the Sega CD is a crime against Humanity. The music and their voices are beyond what you would ever expect in a video game.
These are just a few, I'll list more when they come up in my head, but what others can anybody think of? Maybe some on RU I haven't played yet? lol