I would say it's all in how you charge customers. As long as you have legit copies for each machine being used you should be able to find a way to charge people without actually charging them to play any specific game. It might just be as simple as charging for hardware use and not for playing a game.
Just realized you are talking mostly about consoles. In that case you may just want to look into buying rental copies/licenses. You should be able to get info how to get them from any local video store. Then you are just charging rental fees except that the games never leave your store. Not a bad idea.