I've been organizing my media center recently with Plex (which is amazing) and had a pressing desire to sort out the rather large Asian movie collection I have. Turns out late 70's Kung Fu movies are almost always misnamed, and Korean movies have a habit of completely changing their English release name about a year after release. So I really needed some good resources to find the original local name (imdb only provides the English name and a transliteration, but not the original characters), the release year and the proper English name. Along the way I pulled these useful resources together:
Hong Kong Movie Database
This resource had almost every Chinese movie I threw at it. At times all I had to go on were the Romanized names of a few of the key actors and a year and I was able to sort it out.
HanCinema
The primary resource I used. It had easily 90% of the Korean Movies I needed to work with, autocomplete, aliases, release years, posters everything.
Korean Movie Database
Another good resource, but a little clunkier than HanCinema. Some of the movies that weren't in HanCinema were here.
Daum 영화
The Korean Language movie database. It's all in Korean so it's a bit tougher to use than the other two above, but can be a good last place to try.
Virtual Korean Keyboard
Sometimes, you really need to search for movie in it's native language. This is a great way to get the Korean titles written somewhere so you can copy-paste them out.
Wikipedia
A surprisingly good resource for Japanese Movies and Anime. I was almost always able to find the name of the movie in the original Japanese.
Hope these help.