Azure. Its so vast has something for just about anything, and isn't crazy expensive if you implement whatever it is you're doing with cost in mind.

Used different features of it at old companies Storage (blob/table), service bus, application insights, app centre, event hub, functions etc...

Currently at a company that is slowly moving over to Azure which is a great process to be apart of. Get to spend a lot of time investigating what is available as it seems each and every time I come to use it, its grown substantially.