Cheap
A friend used to say being a poor sport was the second worst thing you could say of someone. The worst being that they're a liar. Later on, I augmented that to hypocrite.
Today I came up with number three.
The third worst thing to say, is that they're cheap. I don't mean financially cheap, but mean of spirit, petty. Taking unnecessary shots at people is cheap, for example. Kicking people when they're down is also cheap. Cheating at cards, self-gratifying behaviour at the expense of another, using others as the receptacles for your own shortcomings. These are all cheap.