Hello Can someone help me with a good revenge Korean drama ?
Try: Temptation of wife Pink Lipstick Equator Man Temptation of an angel IRIS City Hunter
Maybe.... Innocent Man?
I think City Hunter is the best revenge drama. It's not one of my favorite genres because when it is done badly, it's really bad. But City Hunter is unique in the genre in that it is very thoughtful in regards to the revenge and also it has the best villain because they actually make you feel some sympathy towards him. I also enjoyed Equator Man for the most part, although it had its issues. But the acting was really good and it was very beautiful to look at. Innocent Man too because it is very different than other revenge dramas I've seen, and because of Song Joong Ki (enough said).

I'd avoid A Man Called God and Temptation of an Angel. They are terrible (and even more so because of how their awfulness brings down the great Song Il Kook and Bae Soo Bin, respectively).
City Hunter is really good.

I think Bridal Mask also have some revenge aspect but I haven't done it so I don't know if it's good or not ><
City Hunter. Bad Guy (don't watch if you're endings lover). Bridal Mask. Temptation of a wife and Temptation of an angel but those two dramas are really long. However, they contain a great revenge plot. A love to kill (melodramatic) IRIS If you're looking for a strong revenge plot, I would not recommand Innocent Man, it does sound like revenge but it's really not.
I watched all of them see my list here

Try to watch... Sorry I Love You
Iljimae Tree with deep root Bridal mask The Baker King (im not sure i forgot) Giant >>> the best but Long Resurrection The Devil The Equator Man Iris City Hunter Time B/w Dog and Wolf Little Girl K A Man's Story The Chaser (i think) Nice Guy (i think)
Little Girl K is best in revenge in my view... City Hunter - Great Bridal Mask - So so Innocent Man - O.o Glass Mask....I watched up-to ep 9 and its very good. Yellow Boots....I watched around 20 something and I loved it. On-hold because not fully subbed. And I heard Pink Lipstick and Temptation of Wife are great...
A Love To Kill Giant Green Rose Iljimae I'm Sorry I Love You Prosecutor princess Resurrection Story of a Man Swallow the Sun Temptation Of An Angel The Devil The Princess's Man Time Between Dog And Wolf Also Queen of the Game and A Man Called God but I didn't wach them yet.
Five Fingers A Man's Story aka The Slingshot
City Hunter and Temptation of Wife Is the most famous Revenge Dramas that i've known
I see you watched Maou, try the Korean version The Devil. Also agree with everyone else City Hunter is a must.