I've gone through a few themes this past year, but I landed on Sarah Drasner's Fortnite theme in July.
I love it even though I've never played Fortnite (I guess I'm not cool lol).
The theme out of the box is great, but you can enable a legendary mode via CMD + Shift + P (CTRL on non-Mac machines).
It allows you to have a jumping llama when VS Code starts among a couple of other things like flaming tabs.
Check it out on the VS Code Marketplace: Fortnite VS Code Theme