Positive Messages/Role Models: The main female characters are often represented as the strongest and the most capable over most of the male characters. Buffy Summers is a strong girl (in both mind and physical strength) who faces challenges both typical to girls her age and supernatural, often respectively. Although this show portrays strong, intelligent young women, many are often dressed too sexy in many situations. Lots of makeup and spoken worries about appearance often show up on this television show, without giving a clear message that women do not need to be sexy to be likable. Although, saying that, I'll add that one character has shown that she is likable and intelligent and strong, while never needing to wear skimpy clothing and heavy makeup at the same time: Willow Rosenberg, who, may I add, is the first character to be featured in a long-term lesbian relationship on US television. Awesome, right? Talk about a positive message. But I'll also add, scary situations come up a lot that include heavy topics such as rape, abuse, addiction, law-breaking and so-forth. Definitely a mature teen-oriented show. Think about what you can "handle" watching. Do you usually watch shows with similar content? How is it different from what you normally watch?
Violence: Violence ranges from cartoonish to gruesome. Don't watch if violence is not your thing.
Sex: Many of the lead characters have sex, at different times among the span of the show. There have been several heavy sex scenes, although some on the more mild side. Still, as the characters mature, the sex scenes become more frequent. Both male and female characters think a lot about sex, although this is something that is typical for their ages, and so doesn't seem to be too much of an issue. Some young women dress in very skimpy clothing, although they are often portrayed as moral characters.
Language: Appropriate for a teen audience.
Consumerism: Not a frequent problem.
Drinking, drugs, & smoking: Characters drink. I can only remember one account where two of the characters under the influence are in high school. While characters are shown drinking every once in a while, it is very often shown in a negative light, most notably the episode "Beer Bad". Also, some smoking, and a magic addiction is treated in the way a drug addiction would.