Game media preservation, where?

Sometimes, a video game enjoyer just wants to be showered in nostalgia.

Sometimes maybe they just want to be more immersed before starting a playthrough of a classic game.

Maybe they obsessively keep a (digital) journal and want to give it a bit more color by including trailers, posters, commercials, you name it.

So I wanted to ask what your go-to sites to get all that good stuff are. Are there any, even?