As a teen...things I'm seeing my peers drawn to, even in my little Christian bubble..
Sex...you're not cool if you're a virgin...another thing is not-sex. A lot of teens think not going "all the way" is okay.
Dating....so many people are in unhealthy relationships and date for recreation, subjecting themselves to more temptation, and "missionary dating" as they call it.
Civil Disobedience.....breaking the law is cool rebellious thing to do, even if it's a law you may think is stupid, you are still commanded by God, to follow it (unless it contradicts the Bible, obviously)