Haven't seen any popular ones myself. Maybe try the Queen of Blade game you sometime see ads for on this site? Should be a Chinese browser game. I've played it a bit, which might work but it's not even a hentai game, just some really minor CGs with light nudity (some nipples), so more like a ecchi game I guess? Has a terrible stamina system though. 5 stam per 30 minutes, stages cost 5 stam just to run and the game isn't particularly friendly towards free players as so many actions require cash currency, which you can get a decent amount in game.

It's hosted by Carolgames, they only have 4 games though and 2 of them are ios games while the other one is literally just a clone of Queen of Blade (which I wouldn't be surprise if just a clone of another game).