Had a bit of heated debate with a friend earlier over which game is better and more likely to win GotY; Skyrim or Arkham City (though it is possible both will get it). He claimed that Batman trumped Skyrim in graphics and gameplay and also said that there was at least 100 hours of game to play in Arkham City if you completed all the sidequests etc., and therefore could be comparable to Skyrim in the amount of content available. Personally I think that Skyrim has better graphics (though the character models are probably slightly worse), gameplay is too different to be comparable and that Arkham City cannot compare at all to the amount of content Skyrim has and the amount of time you can spend playing it.
So what's your opinion guys, which game is better? And why?