Firstly, the hyperscale providers size their VMs differently, so it is generally not an apples to apples comparison. The best way to compare cloud environment is to consider 3 year cost of ownership, and try to price in various components/elements you might use such as big data stores, VLANs, autoscaling, tiered storage etc.

It is my opinion that the variance in pricing over the long run is no more (or will be no more) than 5% for these hyperscale providers over the long run. So your decision should be based on the type of applications you are trying to build in the cloud. If you are a microsoft "house", then it might make more sense to consider AZURE since they make it easier to port diretory services and licenses to their cloud. Likewise if you are a google house.

Obviously AWS has a lead in the market with regards to tools and functinalities as they were early to the cloud game, but MS and google are catching up fast. My personal choice of IaaS is google cloud because their interface is very easy to understand, but frm a customer support perspective, AWS and AMAZON are far better. Also, AWS and google frequently provide free credits for a period of time so it would make sense to try those out to see what works best.