After working in the cloud for about two years I have a number of thoughts about some key vendors. Each vendor is different and there is no outright winner.
Here goes for Amazon:
Pros:
- Most advanced set of Cloud features in the industry
 - Largest choice of RAM, Core, and Disk options
 - Most flexibile hard disk solution (EBS)
 - Pre-pay gives generous discounts (41%+)
 - Fastest instance resize solution
 - The one to beat
 
Cons:
- Zero free customer service
 - Poor paid customer service
 - They are still over priced
 - A number of big outages over the last couple of years
 
