"You're not like other girls"
"You wouldn't understand"
"Try me"
Siblings saying "Sis" and "Bro". As Francine says in American Dad, it's clunky and expositional.
Using a cigarette and a leather jacket to convey that a character is a cool, nonchalant bad boy type.
Female characters who are in a situation where they don't have access to feminine hygiene not having an issue, eg. perfectly shaved pits (Kate in Lost lol)
That one character who stays quiet about their zombie bite or other debilitating injury until it's TOO LATE.
And lastly, the trope I hate the most, people who don't double-tap!! Make sure the fucker is dead before you turn your back on them!