Well, I've been building up a list of that very thing over the years, but they aren't "businesses", because they would consume money, not generate it.
- A 24-hour cafe. With good food, comfy chairs, and bulletproof wifi.
- A local-to-me good hardware/houseware/hobby/general store.
- An office product and art supply outlet for cons, conferences, and tradeshows. Have a booth or table setup, sell art and office supplies, do prints and photo color prints, flat scanning and item scanning, DVD burns, etc.
- A nationwide chain of Gentleman's Clubs. (For all genders of gentleman, of course.) Think "work from the cafe", but for executive types.
- A pagan parochial school. With weekly services.
- An atheist parochial school. And yes, also with weekly services.
- A true teaching university. Optimized for learning and doing. No PC bullshit, and no tenure.
- A media production studio. That put storytelling first, did faithful adaptations, and worked with the internet and the fileshareing networks, not against them.
I can expand and expound on any of these, and the synergies between them, at length.
Most billionaires are so boring with what they do. Even the ones with the flash and sizzle, its boring mainstream flash and sizzle.