Here’s one I didn’t know – in the early days of the Ouija board, a Chicago company made a clone called the Volo and tried to take over the talking board market.
Troy sent me this link.
The ouija company seems to have put them out of business as part of their legal work – they must have had one heck of a legal team. At one point, they even tried to claim that the boards were not toys, but religious tools, and, hence, should not be subject to taxation. They lost, though.