Depends on the lane and role? Check out Elementz tier list give you a pretty good idea.
Bot lane: Vayne, Graves, Trist, Cait, Kog.... etc?
Top lane: Tryn, Riven, GP, Yorick, Irelia..... etc?
Some of the jungle can carry too like Skarner, but i dunno if he is AD.
Technically bot lane ranged AD is the one that is most likely to carry late game. I think Vayne is generally recognized as the super-carry. She can destroy a whole team with her true dmg given someone is tanking for her (and she needs cleanse).