Null's Clash, in my opinion, is the best as well as popular private server to play Clash of Clans. Playing on this server can give you more fun and thrill even than on the official server, due to the fact that on it you will immediately after installation get access to unlimited resources, as well as to all possible levels and devices that are present in the game. In general, this is a really cool server, you can learn more about it and download it here https://nulls-clash.com/download/.