I've always had good experiences with the MacPorts gcc and nowadays they even have clang. Download MacPorts, run "sudo port install gcc", and go get coffee. Alt

I've always had good experiences with the MacPorts gcc and nowadays they even have clang. Download MacPorts, run "sudo port install gcc", and go get coffee. Altogether much less than 3 GB. The only caveat with MacPorts is that you should make sure that the package you're downloading is fairly recent since some maintainers neglect them.