I'm not a big zombie movie person. I like Night of the Living Dead, and that's about it. So I was surprised when I found myself really liking walking dead, a lot. One thing that hooked me was how well they pulled off shots of a post zombie-pocalypse Atlanta.
This is the demo reel from Stargate Studios, the company behind The Walking Dead effects, highlighting how they composite in graphics and animation to make The Walking Dead look so good. It's awesome, and it gives a good sense of how much time goes into making those shots.
The video is a little long, but try and stick with it at least to 1:28, when they show how they did the now iconic half a zombie crawling through the park.