I took Harvard CS50 through EdX and loved it. It's how I started learning to program. I tried a few other classes, but they weren't as good. Like any educational system, the quality depends on the course designers, but the platform itself was great.
I didn't pay the $99 or whatever it is for the certificate. I was learning to program as part of a job I already had, so I didn't need the credential, and I didn't think a certificate for an introductory semester-long CS course would have helped much in any case.
You're right on not paying the fee, i actually want to help my friend who dropped out of high school (for personal reasons and not bad grades) to get back on his feet by studying programming on his own and perhaps work with me one day :), i've tried this course just to see how it looks like today and it seemed the best course for beginners in my opinion because they explained everything in such a simple way.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.