First off - im not affiliated with any of these projects. This is just my opinion.
Data can be gathered from: http://serverbear.com/
I started out with AWS, and I still use it day to day at the job. We can't really move away from AWS and their VPC ability, because we have a big full mesh network between offices, datacenters and the cloud.
AWS is the big daddy, and the most expensive. And you'd think the most powerful.
Then on the personal side, I went to Rackspace. I ended up there because I did a lot of experimenting with OpenStack and I wanted to see how a big company would implement it as a SaaS or IaaS product. And Rackspace has done a good job creating their own interface to the product, but the service interruptions are atrocious. I went an entire day without being able to shutdown or create a server.
Rackspace is the middle of the road, and is a much cheaper alternative than AWS, but lacks the VPC and advanced features offered in Amazon. But for personal use, 15$ a month for a small server is just fine with me.
Then I found DigitalOcean. My first thought was, "wow, what a clean, bootstrappy feeling interface." And my second thought was "holy shit, 5$ a month for a tiny instance WITH SSD?"
Yeah, SSD. So I've been using DO for a few months, bringing up servers from small to large and working on my little personal projects and its cost me a total of -- not kidding -- $8.50. And I cannot explain how happy I am that the instances are mega-mega fast. The speed puts Amazon to absolute shame in the general server arena.
DigitalOcean is the cheapest solution for personal servers, and actually, somehow, offers the fastest disk IO performance. You can see at serverbear that a 512mb, 1 processor, 20GB SSD instance costs $5 a month, and performs at a speed of roughly 280MB/s, where as Amazons $380 a month extra-large server caps out at 1/4 that speed at 55MB/s.
So, in conclusion, I have learned that if you need a fast cloud server on the cheap, and you do NOT need the full feature set of AWS, then DigitalOcean is the way to go.
Update: DigitalOcean has had a positive vote on bringing up an OpenBSD image. Between this and their internal network, it is possible to hack together a secure poor-mans VPC. I wouldn't use it in production, but for home use this is a big plus. Basically for $5 a month I can whip up an OpenBSD packet filter/Isakmp daemon that will give me a speedy, super configurable, secure vpn between my house and my cloud in DO.