Leona actually kind of sucks. I like her, she has cool abilities, but she's on the underpowered side. Chogath is rly good.
I play Galio and Alistar in ranked when I'm forced to tank (Galio only against magic-heavy teams).
Elementz finally updated his tier list, for anyone who cares.
http://rog.clgaming.net/tier-lists/44-solo-queue/latest
I don't always agree with it (scratching my head over Trynd/Xerath in the top tier), but it's usually a pretty good indicator of what people are playing at the higher ratings.