Entirely depends on your use case most likely. While thus far I've mostly only used these services for side projects & academic research, I will say that I found Google Cloud to be the easiest to use by far for a casual / new user. The quality of the tooling, UIs, libraries, and documentation is just exceptional. I've found getting most things up and running there is a breeze and downright enjoyable, which sharply contrasts to my experiences using other services.