Any Riven skin. For some reason I see a lot of people hating on her skins. And I can't call either of them favorites, but I've almost never seen other people using Infiltrator Irelia and Warrior Princess Sivir. The latter is understandable, though.
The time is out of joint. O cursed spite, that ever I was born to set it right! http://i.imgur.com/wRsnLsf.gif
Boneclaw Shyvana is Best Shyvana. For some reason, though, people seem to massively prefer the merely really good Ironscale Shyvana. I guess they can't handle Boneclaw's majesty, so they go for the close second.