PB Mining
My understanding is that PB Mining had little details hidden in the fine print that makes investing with them very unprofitable. One example of this is that a one year contract starts at a certain time, say the first of May. Then an investor will buy the contract on June 4th. The contract is set up so that the year starts on May first but the investor does not earn any mining rewards until the contract is paid for. This essentially means that they receive over of month of your mining rewards and drastically affects your possible ROI.
The most "honest" cloud mining service is CEX.io, although investing in GH/s from them is also probably a losing deal as they are probably too expensive to ever become profitable. Another issue with cex is that they control very close to half of the network and many people do not like this. I believe yesterday they got up to ~45%, although I don't know where they are now.