My faves list, I don't think any of them have an anime? Maybe Doukyuusei does.
http://www.mangago.zone/home/mangalist/995611/
Love is an illusion, this is where I fell in love with with omegaverse
To take an enemy's heart - recommended
Heartless
He's so beautiful
also Under grand hotel
Rogue
Rouge**
What is you guy's favourite yaoi manhwa/manga of all time? One that doesn't already have an anime adaptation please