We use Amazon Elastic Compute Cloud (EC2) in all areas of our organization. A lot of our legacy infrastructure is in EC2 that supports every person in the organization. It's a great way to build a computer resource, on the fly, and in many different instance sizes. The resource selection is amazing.
Amazon Elastic Compute Cloud (EC2) for me is the easy choice for servers. There are so many tools out there, specifically terraform and packer, that allow easy integration with EC2. It is great for any sized company. I have also used Google and Digital Ocean, but my first choice will always be AWS. The tools are invaluable.