I am trying to branch SC, QM, OD, and EN in that order. I am GAARNG. Which one has more opportunities in the civilian world?

Not much in your profile to help us provide a good answer. I worked 16 yrs in private sector after 22 in the AF. I recommend Quartermaster or Signal. Quartermaster jobs may translate to civilian supply chain management jobs. Signal jobs often have common knowledge and skill sets with civilian communication and IT jobs. If your degree fits into one of these two groups it’s a plus.

It depends on what you want for civilian career. SC is good for IT. EN can help for engineering. Some civilian jobs are branch immaterial or care more about college major

Signal if you want to go into IT
Quartermaster if you want to go into supply chain logistics. Your CIV job experience will be more important than what codes are on your ORB though.