I started off teaching my self html, php, JavaScript. Then got into game programming and learned Java. Have tried Python to make a simple Reddit bot. Don't like c or c++ because I learned Java first and they seem strange. I've tried raw WebGL (no framework) and with framework (three.js). Have used MySQL but hate that it's so insecure and I'm forced to use mysqli. Currently interesting in making web apps with node.js as the backend. I've made a todo app with node and express as the framework. I use nginx as my server to reverse proxy to my node app. I use MongoDB for the database. Know some Linux so I can ssh into a VPS and set up my app there. Using foundation 5 as my front end framework. Also know a bit of angularjs. Any ideas of what I could be building? Also have I've used websockets and am currently interested in webrtc.
You obviously seem to be willing to learn pretty much anything so I suggest you, don't think of what you can do with your skills, just choose something that you can be passionate about and do it, the stack can come after.