In the following order?
Apple (I own zero Apple products)
Microsoft. This one would hurt, but I could manage.
Facebook. Need it for coordinating non-profit activities and contacts wit schools, but could go back to email.
Google. Probably not. They do my DNS for all my project websites, I buy my domains through them, they host a dozen or so email accounts, I'm on Google Fi. Yea, fucked there.
Amazon. They own me. I have stuff running in AWS, I have Amazon credit cards, and buy tons of crap weekly that I cannot get locally, and may not be able to get at all if there was no Amazon. And then you get into the books I run through.