Quoting Noneya Business:" GED's actually take a lot of work to get. Most people don't know that. They think it's a simple test ... [snip!] ... but more people look at it that a high school diploma is better because you stuck through the years of high school to get it."
Depends on the program.
I had to attend class for three days to do practice tests, passed them all, and then had to wait a month for the actual test. I only passed my freshman classes and two sophomore classes and did about two months worth of the rest of the sophomore classes and two junior classes in high school.
On the other hand, they shut that program down and my brother had to go through a different one. They wouldn't let him "test out" of the classes like they did with me. He had to attend a certain amount of classes before he was allowed to test.
The high school diploma will always be better even if they are supposed to be equal. It shows that you worked through the four years instead of quitting, regardless of how hard the GED is to get. I'm pretty sure they are looked at equally after you get a college certificate, though.