If you're talking about hosting your startup's landing page, stick with Github Pages: https://pages.github.com/. Free, super quick & easy, with custom domains to boot.
Personally, for almost any product I start here. Even if you do need server-side infrastructure for the product, hosting all your marketing pages on GH pages is probably the right choice - they're going to be better at reliably hosting and serving static content than you are. Focus on your product instead.
When I do need server-side logic I then usually go for Digital Ocean, because they're very cheap, pretty great, and far less complicated to manage than EC2. It's also pretty easy to set up Dokku: https://medium.com/@pimterry/host-your-node-app-on-dokku-dig.... With that on top you then get a quick & effective Heroku-style deployment experience, at a fraction of the price.