For those of you who don't know what a tsundere is:

Tsundere (ツンデレ?) (pronounced /(t)sʌnˈdɪə(r)/ in English or /t͡sun.de.ɽe/ in Japanese) is a Japanese concept of a character archetype which describes a person with a conceited, irritable, and/or violent personality that suddenly becomes modest and loving when triggered by some sort of cause (such as being alone with someone). It can also describe a contradictory personality which is good-willed on the inside, but with a harsh attitude on the outside. Originally found in Japanese bishōjo games, the word is now part of the otaku moe phenomenon, reaching into other media such as anime, manga, novels, and even mass media.
I personally loved them when they first started popping up in anime and manga but now it's like an unspoken rule that every single show has to have one of these. Not only that, every strong female lead is also considered a tsundere by people who don't really understand the meaning of the word.

I say they should give it a rest already and start using them more sparingly.