I want to watch movies or dramas that contains mystery, detective, investigating, and most of all thrilling. BUT NOT A HORROR MOVIE/DRAMA PLEASE. 
It can have slight humor or romance but mostly about mysterious stuffs. Something that will make your brain you know, think or enhance. Haha idk the term. Something psychological. Please do help me:) Thank you :)
P.s. Where can I watch most dramas and movies?? What website or app that contains a lot of movies and dramas to be watched online and can be downloaded? Thanks u again. 
Mystery is really not my thing. The closest I can think of is Vampire Prosecutor (not a horror but has a Vampire that uses blood to help solve crime)

I use Viki and Dramafever mostly, both have streaming but I don't think they have download. They both have area restrictions so I don't know how well they will work for u. But definitely give Viki a chance. Hope this helps.
Drama:
Angry Mom
Bad Guys
Gap Dong
God's Gift - 14 Days
I Hear Your Voice
Kill Me, Heal Me
Liar Game
The Bridal Mask
The Princess' Man
Two Weeks
White Christmas (it will be hard to understand in the beginning but keep watching, it's really interesting)

Movies:
Confession of Murder
Secretly, Greatly
The Attorney
The Con Artists
The Crucible

You can download in:
http://myasiantv.com/

http://doramax264.com/
http://dlkdrama.com/

http://www.dramacool.com/
you can't download there but the quality is pretty good to watch online ^^

I love crime/mystery dramas so I will share what I have watched and liked. I don't know if you have preference in Korean or Japanese dramas but there are the best I have watched:

Korean dramas:
* Missing Noir M (2015)
* White Christmas (2011) (its amazing psychological drama)
* Bad Guys (2014)
* The Virus (2013)
* God's Gift - 14 Days (2014) (the twists in the story will keep you on your toes until you solve it)
* Ghost/Phantom (2012)

Japanese dramas:
* Galilleo 1 & 2
* Higashino Keigo Mysteries (2012)
* LIAR GAME 1 & 2 (Its not a crime mystery but the games inside will make your brain spin to find a solution)
* MR.BRAIN (2009)
* MONSTERS (2012)
* Detective Conan: Kudo Shinichi e no Chousenjou (2011)
* Tantei Gakuen Q (2006)
* The Files of Young Kindaichi Neo (2014)


Movies:
* Kindaichi Case Files Gate of Jail Private School Murders (2014)
* Saigo no Yakusoku (2010)
* The Snow White Murder Case (2014)

* Suspect X (2008)
* Midnight F.M.(2010)
* 7 Days (2007)

I hope you like them!
You can watch online at:
www.myasiantv.com
www.gooddrama.net

THANK YOU SO MUCH!!! I've watched White Christmas, it's amaaaziing!! Currently watching The Crucible :)
I'm surprised no one has mentioned Special Affairs Team TEN season 1 and 2.
You should watch OCN stuff. They make THE BEST mystery/thriller dramas available and the series aren't too long (but some have more than one season but you don't HAVE to watch all of them if the show is not good. Some of the OCN dramas are:
God's Quiz (my all time faves and have rewatched all the seasons at least 4 times and it never gets old)
Missing Noir M (haven't finished it yet but the pacing and storylines are amazing)
Bad Guys (haven't finished this one either but the acting is phenomenal and story is suspenseful)
Special Affairs Team TEN (Liked all of the individual stories but wasn't a big fan of main overarching storyline)
Dr. Frost (kind if slow for me but I know a lot of people who avsolutely loved this one)

For movies, other than the ones that came up, i would reccommend blind. 
It was one of the first korean movies I saw that i liked so I don't know if I would feel the same way about it if I watched it again but it's definitely worth a shot!
Currently watching the girl who sees smell and it has got me and my boyfriend hooked (he normally hates watching kdramas!) 
Hi.

My recommendations may be a little weird. Why? Cause they have ghost, and comedy and plot twists...

Korea:
Arang and The Magistrate. So boy meets ghost girl who black mails him to uncover her death.

Queen In Hyun's Man. Boy try to uncover the plot against his queen and save her. Falling in love in the process...

Rooftop Prince. Boy most uncover the death of his wife.

Who Are You. Girl who can see her dead boyfriend ghost tries to know what really happen. And she is a cop.

You're all Surrounded. 4 rookies most survive their boss, their dangerous work as police officers and uncover dangerous plot.

Japan:

Zettai Reido Season 12. Police Officers trying to solve cold cases.


Where to watch?

www.justseries.tv

I hope you enjoy them!