Halong has created a Bitcoin Miner that is set to directly compete with the current market leaders. The DragonMint 16T is rated at 16TH of hashing power and costs $1595.
MinerGate is a cryptocurrency mining brand. The platform provides convenient software for mining a number of crypto coins and a mining pool in which this software or one of the supported side apps can be used. The platform was founded in 2014 and has gained a multi-million user base since then.
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.
BTCSweet is a UK based cloud mining company launched in 2017.
BTCSweet charges no maintenance fee. The contracts are "lifetime" (it means that there is no determined duration of the contract and it finishes when the chosen mining plan becomes unprofitable). The platform accepts payments in Bitcoin, or by Payeer, Perfect Money or PayPal.