I thought of jumping the gun with RoyalHash - but came across this thread and wisely kept my BTC. I remember when I used Cex.io a year or so back, never had problems with them back then (not sure what their reputation is now).

If you're wanting to make some BTC, it's better to use a skill you think you're good at, and sell the service/product for BTC. It seems like a less riskier option than investing (besides the already fluctuating value in BTC), and your success will depend on the quality and demand of your product/service. That's why I'm trying to sell my BTC script - so I'm able to break even and offer something that I perceive to be of value (if I got enough interest, I would start a faucet).