The above video was made by Adam Pinkman with Grand Theft Auto 5 on the PC and a variety of mods. It's fun to go back and watch the live-action trailer for Skyrim it's meant to recreate; Pinkman does a great job of nailing that trailer's look and feel.
This is actually based on a5 mod Pinkman is in the process of creating, and he thought recreating an existing trailer was a better way to sell people on the idea than just showing a general video.
"It was quite challenging with the scenes," he told Polygon. "I had to use other mods to accomplish these types of shots for instance. When people are panicking and rushing all over the streets, I used the Chaos Mod."
The hardest part? Unsurprisingly, it was the dragon. "Because it was all CGI, I had to rig the dragon, animate it, and render it in a 3d software, and then composite it," he explained.
His plan is add animations to the main character and, of course, add the "FUS RO DAH" shout to the modification, but this video is already a great mixture of two very popular gaming worlds.