a.) Video game music (especially to a game over two decades old)
b.) Jazz
c.) Covers of both of the above
I'd respectfully disagree. Ok, video games are nerdy, but jazz? In my experience jazz, while indeed horrendously niche, is frowned upon mainly because jazz listeners are seen as mildly pompous and arrogant about their music preferences (they enjoy "cultured music", you know). People whose attitude to music reflects "connoisseurs"' attitude towards wine: looking down on those with "cheaper" tastes, or even pretending to have more "refined" tastes in order to be able to do so. Whether that's true or not is of course irrelevant.
Now, what you're really looking for is a genre time forgot. A genre people
grew out of. A genre 99% of people relegated into the "What the hell were we thinking" box.
Basically, what I'm saying is, chiptune Righeira.