Code Avengers makes their material engaging and interactive, which aids with understanding and retention of the material.

Explains what everything is before you must use it, unlike Codecademy, which just kind of tells you to do stuff. To figure out what everything is exactly, you must either look at the glossary or google it.

Not only do they offer Python, CSS and HTML, and all the works, they offer them in context packages, where you can work on a project that utilizes one or the other. Also, there are different recommended tracks for different purposes - web designer, etc.