Depends what group I'm running for / playing in.
Most of those I game with are in 30s, 40s or 50s, and mixed genders. We usually would be PG or PG-13 for violence, gore, horror, occasional cursing, and out-of-character off-color jokes. We rarely "fade to black" because we just don't hit material that would need it.
Compare to when I was a teen or in my 20s when we'd play pretty much R. But there was a lot more "exploration" of certain topics back then, such as romance & dating/marriage, torture, body horror, attempted genocide, and other things that pushed the boundary up. But even in the heavy drama soap-opera like superhero game we didn't have any episodes go NC-17.
The game I run for my kids, niece and nephew (mid to late teens) are firmly PG. Not G, though one person gets squicked by gore so we keep that down. We also use an X card.