Bans.
I don't understand them. Well, I do, but what I don't understand is what people do with them. Today, I saw a Sona, Orianna, Karma, and Varus ban, of all things. Why do people ban certain champions, which are either very unthreatening compared to others, or very easily counterpicked (see Darius)?
Personally, I prefer to ban champions which can be VERY threatening to teams later on. Malphite, Blitzcrank, Teemo, etc, all are champions which bring a lot to turn things in the favour of an entire team throughout an entire game, rather then just a vaguely irritating laning phase. So who do you like to ban and why?