There's no safety word for Shao Kahn. After slapping you around like the dirty little bitch that you are, he'll stop fighting mid round just to laugh at you and trumpet proudly, "you suck." He comes complete with unblockable moves and extra health to supplement the soul-crushing mockery that has given permanent heart problems to anyone that's ever been to an arcade. What's most evil about the laugh is that no matter how much you act like you don't like being whipped and slapped around by a large, sweaty codpiece, you always seem to come back for more.
There's something about Batman that really captures the cultural psyche. He's an ubermensch, a regular Joe, a detached jerk, a sympathetic victim, a brilliant mastermind, and a clueless social idiot. Then there's his perfect foil: the Joker. Batman's arbitrary set of codes and rules is parodied by the Joker's arbitrary thirst for chaos. Similarly, Batman's resolute stoicism is parodied by the Joker's wild torrent of emotion, including an immediately recognizable laugh. The Joker wears his heart and sometimes other hearts on his sleeve. When things are going his way, he makes no secret about it. During his time as Arkham Asylum's "warden" he spends a lot of time laughing. He's always one step, cliff, and giant mutant guard ahead of the caped crusader. Even until the end, the Joker gleefully exploits Batman's laws and predicts every move he makes, cackling every time the Dark Knight walks into another trap.
There are plenty of great menacing laughs in the Final Fantasy series; the signature sound byte of Kefka, the "Gya ha ha" and "Kya ha ha" of Heidegger and Scarlet. But the most evil, menacing laugh in the series comes from Final Fantasy X's Tidus and Yuna. The characters burst with as much personality as expected from a Final Fantasy game and for the first time, players can hear their heroes emote thorugh admittedly spotty, but overall strong voice acting. Until the laughing scene. The two leads overlook the city of Luca and
just because. The laugh was awkward, robotic, and would not end. Anybody unfortunate enough to endure this scene with a friend, roommate, or family member nearby had to justify their life choices up to that point.