One of my goals for this year is to finish at least two courses via Udacity. I specifically went with them because they have a range of courses of relevancy to my work and particular areas of focus, it has a good reputation for its content, and it has a lot of free course offerings. Free is good when money is tight. Now, sure, I could probably ask at work to have them paid for, but I wanted to dip my toe into courses, so free is also a better option for that.
The Udacity interfaces are nice! Clean, slick, professional, and they just work. I never had to reload or deal with crappy non-working video or the like, they kept it simple. And while the course is free, it seems to be treated with the same quality I presume the paid courses have, with clear, well-written text, quizzes that include both multiple choice and coding quizzes that are checked by the machine. I have no idea what awesome programming is behind the checker, but it generally will catch mistakes and give you enough info to help you fix them. I only had one place where I finally gave up on trying to fix the issue to its preferences because the error message wasn’t helpful about what I was doing wrong.
Now I can’t speak for the paid courses, as I haven’t taken any, but if you are looking for good free courses on programming, I’m tentatively giving Udacity the thumbs up. I have a few more courses in my queue and I’ll certainly be posting if I find the others don’t match the quality of this one.