Although NiceHash is usually regarded as a mining service, it's better to say that it's a kind of a platform for selling/buying cloud mining contracts. What is special about NiceHash is that users can opt for both selling and buying the hash power on this platform.
F2pool is a Chinese multicurrency mining pool founded in 2013. Now it has servers located in the USA, Canada, Russia, Singapore, and several other countries. The pool has a big number of supported coins. Currently, it is possible to mine around 40 currencies on F2pool.
Based in Romania, Costa Nord Mine offers Ethereum cloud mining services, allowing users to purchase hashpower without having to deal with complex hardware and software configuration. Costa Nord Mine offers mining services and a variety of mining-related solutions for small and large investors.