There are plenty of threads on this subject. Below are just two. Please use the search function, it's a rule you agreed to, thanks.
Further this question is really subjective, since it depends on what you want to learn, what you hope to achieve from said course(s) and how dedicated you are to attaining the certificate etc. Providing this information would really be better for us to help you. Otherwise you are going to get a bunch of different answers, and while none of them may be wrong, they may also not fit your case.