I personally feel like tropes and things are unnecessary and simply label stereotypes that pollute the originality of anime. I definitely have least favorites, though.

I have favorites so way more than one.

Idk. I never cared about deres .

Yes and no. Depends on the character.

I like the concept of yanderes and himederes.

I actually have a thing for Dandere and Genki girls

I don't choose favorite characters by what 'dere' they are (because I like characters like Yaoyorozu (Hero Aca), then I like someone like Yachi (Haikyuu!) or someone like Hazama (Assassination Classroom)

I do hate yandere characters though. They're kind of unnecessary (personality wise) and it's just creepy

I think any 'dere' type can be great if done properly and horrid if done improperly. I feel the idea of 'dere' types is unnecessary in its entirety, but it is always interesting to see them done right. In terms of tsunderes, I adore Taiga Aisaka, and with yanderes, Shion Sonozaki does it for me.