Hashflare is a confirmed scam, first of all. They reduced the length of customer contracts from lifetime (which wasn't really lifetime in the first place, as when profits didn't cover maintenance fees, they would terminate) to 1 year, without consulting any of their customers.

Genesis is probably legit, but nobody says they can't be doing fractional reserve mining. Even though they probably are mining there is no guarantee that they are paying out the right amount, or have the promised amount of miners working. The contracts based on most reviews are definitely not profitable by any means.

Bitforx is new, and unfortunately with no history I just wouldn't trust them with that much money. Plus, there is no reason that they will perform any better than their predecessors.

Just avoid cloud mining. History have proven that it is unprofitable and that's not even mentioning the risks of them running a ponzi or just scamming you.