Besides the fact that I have a referral code, I think Digital Ocean has done a great job of making an accessible, affordable, cloud environment for folks (like me) to spin-up and -down servers for trying new things out.
You can’t beat an average of 55 seconds to get a new server.
They all have their time and place, but for me, DO has been the best option for much of what I want to do.
Their API is simple and easily-accessed, billing is straight-forward, and you can make your own templates to deploy servers from. For example, I could make a template for MooseFS Chunk servers so I could just add new ones whenever I need them to the cluster.
And I can expand/contract servers as needed, too.