The Ghost API provides access to your blog's posts, tags, and users. You can get items, as well as create them. Before accessing anything though, you'll need several pieces of data, depending on your blog settings and whether you're trying to get data or create it. Let's see what we can do with it.
The Internet Game Database is a community-driven site that collects and shares information about games and game-related data. Let's check out the IGDB API!
The Space Telescope Science Institute works closely with the Hubble telescope and its operation. They've made available, through their HubbleSite API, tons of photos, videos, and other data.
The Instagram API gets data about media, but also manipulate likes, comments and much more. Let's check it out!