Garen: Too much power in pubs, too weak in pro play. Lopsided power? Probably.
Whenever I face a Garen in Team Builder, he generally makes things really obnoxious if the game lasts longer than 30 minutes. You've got a Champion who can build pure tank, still rip apart your team's carry with a single E spin, and deal huge damage with his ult that doesn't rely on any scaling. That and if you don't succeed in killing him, he'll quickly withdraw thanks to his Q and W, wait 30 seconds, and then be back to full health without requiring a recall. Once he hits level 16 and has Warmog's and Spirit Visage, he can regenerate around 16% of his maximum health every 5 seconds when out of combat, and thanks to his speed, slow-purge and CC resistance, he can disengage fairly easily unless you wall him in.
People will always go "just kite him!", but they obviously haven't seen how fast a good Garen with a Youmu's can go. Seriously, all he needs is a Ghostblade and then he can build pure tank and still hit like a truck, all while being really hard to peel without powerful knockbacks (i.e. Alistar).
But on the other hand, Garen's only got around a 2.72% pick rate at high tier play, and he's easily counterpicked by Nidalee, Jayce, Lissandra, etc. Coupled with having no gap-closer (his haste doesn't count), and he definitely leaves a lot to be desired at high-level play.
In essence, Garen suffers from a problem similar to Darius: He's an obnoxious wrecking ball at lower skill levels, but sucks at high tier. That and he's simply a menace in Team Builder and Blind Pick modes where you can't counterpick him.
Discussion?