It's amazing that even after all of Anivia's nerfs, she's still one of the best mid laners
Currently the second best mage according to champion.gg. I don't even know if we should count Galio though, since almost no one plays him. I fear Riot will nerf her more at some point in the future.
http://champion.gg/statistics/#?sortBy=general.winPercent&order=descend