Hackers. I play "street rules" just like everyone else, but you can't just be holding your stiff arm out to the side when I get past you. You can't just grab my shirt and pull hard
(that's the key) on every cut I make. When I play people like this, I'll tell them straight out, "play the right way or I'm going to embarrass you." And then I back up my words if they don't.
Guys who reach in for strips on every
shot attempt, regardless of whether they have it measured or not. 80% of the time it's a foul (unless you get the rare guy with legitimately great hands), but you can't call it all the time or you'll look like a b!tch even though your wrist and lower forearm are red after the game.
Guys with tunnel vision when they have the ball. Guys who, even if you defend them well for literally 15-20 seconds and don't fall for any of their And-1 bvllsh!t, will just keep the iso alive for another 20 seconds. No sense of shame or decency with these guys. Guys who will go apesh!t if they catch you with the slightest move one time, but don't want to hear sh!t when you put 5-7 baskets in a row on them.
And like GOBB said, muscleheads posing as ball players thugging it up.