hi guys i wanted to ask the community or the Editors to help Drama Newcomer find good dramas basically when they dont anything about kdrama.. i know there are many sites like Viki and Dramafever where see how many stars they have but they dont have all Dramas and you dont know how good the response in korea was and the Ratings. I know many of you say there are good dramas with not good ratings thats something i know but i also must say there was never a drama that had good ratings and i hated or thought it was a waste of time..
we all have not endless free time so for the start it would be good to have a list with the best drama ratings- i wanted to help my friend but she only likes action thriller and cops dramas which is not so my Genre...

Hello.. I will definitely recommend to your friend the 
CRUEL CITY(8.8 ratings)-an action pack w/ cops involve. He/she will never regret to watch this.. It was the best drama I ever watch..

Other dramas with high ratings that was worth to watch.

Its okay that's love
The princess' Man
Ja myung Go
Secret
One more happy ending
You could try searching with genre filters? Use "top shows" under the "shows" menu, then refine from there.  For example, the top 5 rated dramas on MDL (currently) from only thriller and action genre and from Korea are Healer, Six Flying Dragons, Bad Guys, Two Weeks, and City Hunter.  Change genre and/or country or whatever as desired. :) 

I was personally going to recommend Bad Guys as an action/thriller that I enjoyed, and there it is in the top 5, haha.

I do like the idea of having a short list of strongly recommended dramas for some common categories and think it might be helpful for people new to Asian dramas, but I'm not sure how it would be implemented.  Plus it would need to be updated from time to time.

Or...rereading your post, do you mean the viewer ratings in Korea?  Or just general viewer feedback on a given drama?  Or both?  I think viewer ratings would be especially difficult to compare since they've changed so drastically over time.  Like, nowadays 10% is moderately respectable, but even 10 years ago, that would have been viewed as a pretty poor showing, haha.

Perhaps someone could put together a list of the top dramas (by viewer ratings) by year, though?  Dramawiki has a lot of ratings, but it would be a huge task to organize all that.  And you can look at a list of the highest rated kdramas of all time on wikipedia, but looking at that list, there's not that much that would be all that appealing (or even accessible) to the average international kdrama viewer (and especially someone looking for action/thriller dramas).  And since ratings are so much lower than they used to be, there are very few shows post-2010 even on that list.  Even splitting it out by year, you'll have the list dominated by weekend and daily dramas for the most part, so I don't know how useful that would even be.  You'd have to go further and limit to certain timeslots to avoid that.