Ihad to have a bit of a think before I posted this. Danbooru is particularly not safe for work, I had a fair job finding the relatively clean image above… I don’t really understand all this cartoon porn, but after stumbling across this site, I’m actually quite amazed at the quality of illustration! It might not be everyone’s cup of tea, but you’ve got to admire to skill and time and effort put it. Some of it is laugh out loud funny.
I think it has sometimes more quality than actual porn. plus it is safe, no actor-tress is used/abused ;) still, as you’ve said, cartoon is not everyone’s cup of tea. I found danbooru a few months ago (waaay later than you did) and equally amazed by some of the illustration’s quality. I also thank to tsundere works for the information :)
Danbooru is really a great site. I love it. Great when you’re looking for comics or any reference images to use when you’re drawing.
However, Moe.Imouto is even better, but it also uses the same Danbooru engine.
Safebooru is the Safe-For-Work equivalent of the site.
And it’s fine if you do not understand cartoon erotica, but if you appreciate it or respect it, then that is fine.