Depends on what your interests are. If I had exactly $50.00 /month to spend on online education, I'd consider spending it on either a Coursera subscription or a Linux Academy subscription. The latter is especially valuable if you're interested more in "infrastructure" kind of stuff, and IT industry certifications around things like Docker, Kubernetes, Linux, AWS, GCP, Azure, etc. The former includes more of what you might call "theoretical" material and has more focus on Data Science, Computer Science, Mathematics, etc. (among many other subjects).<p>FWIW, I actually do maintain subscriptions to both Coursera and Linux Academy and have found both valuable. On Coursera I have found value in Andrew Ng's ML stuff, the Johns Hopkins sequence on Data Science, and the Duke sequence on Statistics with R. I used Linux Academy to prep for my AWS Certified Solution Architect certification, and am currently working on the Docker Certified Associate and Certified Kubernetes Administrator certs.