I have had great fun playing through Assassin's Creed 3, I especially enjoyed the story. The collectibles and challenges did not really interest me though. I have only played through the game once. By comparison Skyrim has a very mediocre storyline but I have played through the game many times because of the different styles you can play, and various difficulty. When I got bored with the mage then I just played with my warrior. Assassin's Creed does not seem to have any replay value to me. Therefore I would say Assassin's Creed has a much better storyline, but Skyrim's gameplay is better.