Checkmate with almost all pieces still on.
One of the most satisfying thing in chess is sacrificing a lot of your pieces to force checkmate.
However, equally satisfying is when you give checkmate with almost all the pieces still on the board.
I remember reading in the introduction of some King's Indian book (I can't remember which), that one of the attraction of playing the King's Indian is to be able to checkmate your opponent while keeping as many pieces still on the board and how that's romantic in its own ways.
Now this one needs some cooperation from your opponent, as one needs to make some series of bad moves for it to happen, but still, when it does, it is eerily satisfying.