You get actual feedback from developers on your code, which is useful. Yes having your sites/apps do what it is supposed to do is important, but you need feedback to learn industry standards/best practices and other gotchas that are much harder to learn on your own.

Udacity offers a few different Nanodegrees which provide access to various different courses, project reviews and coaching support for $200/month.
Current options include Front End Web Developer, Data Analyst and Android Developer. See the full list here.

Courses are always made available which means there is no waiting for the specific course you want to run. You can work through the courses as fast or as slow as you want.