haven't actually tried watching any Korean or Japanese dramas myself, but Crunchyroll is pretty good deal for Drama+Anime+Manga if you get a year's all-access membership on Black Friday.
I Am Mullet Death, Undisputed Ruler of the Mole and Crab People! Fear me!
My mom uses Dramafever, Viki and GoodDrama, but I'm not sure GoodDrama is legal... Viki doesn't have a great server, though, so I wouldn't even try watching dramas at night unless you're using a tablet. Also, if you aren't paying for membership, you can 14 minute commercials.