In the plausible, but unlikely, chance that you don't know what these skins look like, here is video of all of them in action!
Original StoryBatman: Arkham City (PC)
has continued the pattern of mirroring the Xbox 360 DLC releases. The pre-order costumes have now been added to the game, but they can only be bought as a pack. The costumes are not available to buy individually. Unfortunately they don’t come with new achievements either.
Download the Arkham City Skins Pack today. The Arkham City Skins Pack contains seven bonus Batman skins: 1970s Batman, Year One Batman, The Dark Knight Returns, Earth One, Batman Beyond, Animated Batman and Sinestro Corps Batman. The seven Batman skins can be used in storyline mode upon completion of main story and all challenge maps.
The GFWL "Arkham City Skins Pack" costs $4.99 / £3.25 and can be downloaded from here