The Mark Cuban Cost Plus Drug Company
I've wondered for a long time how much money could be saved if the non-trivial administrative overhead of insurance companies were removed from all but truly catastrophic cases (where claims start at $10k or more) and medical, dental, and drug costs were paid out of pocket (including via an HSA account).  There are numerous cases where cash-only medical clinics are able to offer up-front pricing for a fraction of what is billed to medical insurance companies.  If Cuban's idea is "we don't do insurance but you're free to pay with an HSA card or seek reimbursement from your insurance company" then this could be a huge winner.