Alright, I know this is sort of a weird topic given MonoGame is really meant for games. But, I mean, it's very easy to load in audio and textures from respective files on the user's hard drive (skipping Content Pipeline, a.k.a using things like
Texture2D.FromStream()), and video playback is coming to 3.7, so...we basically have all the tools necessary to build a decent media center experience. Has anyone ever thought about doing that or even tried doing it? Seems like an interesting project to me.
Furthermore since you'd be designing the UI and a lot of other features from scratch, you'd be able to give yourself the exact experience you want right down to what pixel the "Play" button has its origin point sitting on. I don't know, it just seems like a fun thing to code honestly.