Check out
http://chyoa.com/ (Kinda like a chose your own story type thing full of erotic stories made by members, Some stories are new so they don't go very far but some of the more Older/popular ones have tons of branches and go on forever, Ofc they are full of sex scenes)
http://www.shadbase.com/ and
http://www.shagbase.com/ Shad is definitely one of my favorite artists his work is amazing quality which he posts every week on both sites, But he does have a tendency to do a lot of dickgirl pictures.
As for Visual novels
http://unteralterbach.net/index.en.html is one of my favorites because of the humor, Now I have to warn you guys it does contain Lolicon a lot if you follow the Lolicon route (which is the only one where you don't die) If you plan on playing it I would highly recommend using a
Walkthrough Since there is a particular set of choices you have to make at the start to actually progress. The game is officially free and has options for both German and English without needing any patches.
and you guys already got COC on the list so that's good. That's all I can think of at the moment. Oh and as for flash games one of my all time favorites is Babysitting Cream.
Also you should point out to access "adult" content on Newgrounds you need to be logged in then you need to click on either latest Games, Movies or Art and then Sort out E,T and M ratings leaving A on.
Enjoy.