Gartner has done a lot of your research for you with their Magic Quadrant for 2013! Take a look at this incredibly valuable Infrastructure as a Service (IaaS) platform chart by Gartner.

The market for cloud compute infrastructure as a service (a virtual data center of compute, storage and network resources delivered as a service) is still maturing and rapidly evolving. As each provider has unique offerings, the task of sourcing their services must be handled with care.

There are many providers, but they vary widely in quality. There are many competitors in the market; new entrants continue to launch offerings and existing providers are expanding the market segments they serve. Many providers are more interested in managed services than in the highly automated, self-service market, and consequently the quality of their technology and their investment in engineering varies greatly. Moreover, many of the newer market entrants are very large IT companies with considerable sales reach, which has enabled them to take market share rapidly. Yet these companies do not necessarily have superior offerings. Indeed, many of the better providers are actually smaller, highly innovative companies. Many providers will find it challenging to execute well in this rapidly evolving market. Most providers are able to deliver a basic offering — with reasonable availability, performance and security, and good customer support — but many have limited differentiation and value-add beyond the ability to provision resources quickly. Therefore, significant due diligence must be performed to evaluate providers thoroughly.

Source: http://www.gartner.com/technology/reprints.do?id=1-1IMDMZ5&ct=130819&st=sb