Curl

They killed most of the worst ones. Don't see the point in Gabriel though.

All of them. Besides the zombies of course.

I'd have to say Beth. She just didn't do anything at all in the entire series until just before her death. She was just the babysitter. She had a few good moments with Daryl in season 4. And she was decent in season 5 with the people who captured her. But other than that she was really unimportant. She's one of the very few characters I feel like the writers just didn't know what to do with her