Actually, reggaetón started being slightly more mainstream during the late 80’s/early 90’s. Underground style (in Puerto Rico), which is very… raw, very explicit, very slang… started around the early-mid 90’s and after and is still somewhat around.
Some of those acts cleaned themselves a bit and went mainstream (to different degrees). And all the artists I’m going to name are from Puerto Rico, since those are the ones I know (except for El General, who is from Panama and you can check it out). They all have booty music along with slightly social/political content.
Vico C- Old school… I love that some of his songs are stories. Not too much slang, not very explicit.
Tego Calderón- Newer stuff, I love how he can sometimes combine salsa and other rhythms from my country with reggaetón. Some of his lyrics are explicit, but not as crude as underground. My favorite artist of this genre.
Daddy Yankee and Don Omar- The more commercialized and popular right now, it seems. I like some of their songs, but they’re definitely mainstream. Booty music light, compared to other stuff. Although both of them started more underground, so if you find earlier recordings you may want to check them.
If you want more explicit stuff (this is digging from memory, I hate them) try anything that says “Playero”… Like “Playero 35”, “Playero 36”, “Playero 37”, etc. I remember that was underground when I was in elementary school, and those were the names of the compilations.
For females, Ivy Queen’s stuff is good. Again, she started underground, so the earlier the song the more raw and explicit it is likely to be. She now has changed her image and is more mainstream, but I like her in between stuff (not too raw, not too glam).