Knights

Opponents queen

 best piece

 i dont like the opponents knights

 Both of them or just one

the king, he allows himself to be checkmated too easily

yes

 Of course

My least favorite piece is the one that puts me in checkmate!

Obviously, this is kind of a silly way of thinking about chess, but I usually trade off knights for bishops, which to me is kind of what this question is really about. Rooks are great! I think it was Kasprov that said that, all things considered, the winner will be the first person who combines his/her rooks in one purpose, or something like that. So I guess my answer is officially knights.

cool

 this is a "situationally dependent" opinion 

I take horses in a closed game with 6 pawns

For me it depends what the players skill is

That extra one my opponent has.

Least favourite the rooks.  Not too good with them.

My favourite are the bishops and the knights. ;)

queen

pawn

Whole games are dominated by players trying to keep their 'good' bishop, or inflict a supposedly bad bishop on their opponent, or gain the bishop pair. Bishops are most annoying to me. And they've got a silly name. And I dont quite like the look of them.

My least favorite chess piece is the Queen.

The worst? The pawn. Because of my bad judgement, I always leave tons of holes when moving my pawns which my opponents can use and own me >_>