Haitoku No Niwa
From what it is, it's a smut story about a priest and his lover. It's pretty much smut, but the art and color is so beautiful, the scenes are hot, and the subtle hints at how naughty it is, like the glimpses of his cross, and comments of wearing things under his black robes are sexy.
Karisuma AV Danyuu no Ore ga Omocha nanka de iku Wakenai!!!
Surprisingly, a good manga that's not just about AV actors who have sex for work (**cough**) but are in a committed relationship. It's a hot as hell, erotic story and shows some true sides to AV interesting. There also romance.
Abunai Kurai Aishiteru