Every time Stan stutters the word "friend" in "Kenny Dies".
Play the in-episode curse counter Drinking Game with "It Hits The Fan". That is, if you want to die of alcohol poisoning. Even if you had a relay race with fourteen others, you'll probably all die of alcohol poisoning.
In "The Poor Kid", every time Mr. Adams mentions Penn State, shows his head shot, or says "we like to have fun here" or anything along those lines.
In the three episodes between "Black Friday" and "Titties and Dragons", every time Cartman takes a character through the unnamed homeowner's garden devising a plan to help him and the other character get consoles, and that the rest are there to "help them get through those doors".
In the same episodes, take a shot for each mention of wieners.