Singapore, Nevis and Hong Kong might be the biggest places, next to Panama and most part of the caribbean..... but again, it depends very much on what you plan to do or what you are into.... for instant being a online business the first mentioned makes no sense, since you are limited if not excluded from getting any card processing. If it is for investment, privacy or similar those contries might be considerable.
What else you need to know what be that if you plan to establish a trading Offshore Company, then it would be a good idea to make sure to do a good planning, for instant, if you want to cover the entire world, you might need to have a offshore company and a low tax company for trust purpose towards business partners and customers.
Don't know if it makes sense the baove 🙂