If you want to expand your knowledge on many different areas, including computer science, this is the one. Coursera is a for-profit open course organization offering free and low-cost online classes from hundreds of universities.
If you want to switch career and learn coding on the cheap, this is the one. Codecademy offers user-friendly online coding classes range from novice level to advanced level. It's totally free!
If you are looking for online courses from a famous university, this is the one. EdX is an open-source online-course platform from Harvard and MIT.
If you want to learn in a traditional classroom setting, this is the one. General Assembly offers 8- to 10-week-long immerseive courses in web development, data analytics, etc at 15 locations.