Beyond the Clouds (2014)
Blade Man (2014)
Incomplete Life (2014)
Joseon Gunman (2014)
Line Romance (2014) Drama Special
Mr. Back (2014) - bittersweet

If is ok, I wold like to make the thread for "Spoilers - Happy ending MOVIES"
I'd love to see a thread for happy ending movies!  Pretty please and thank you!  :). 
Done! I've made the Happy Ending Movies Thread.

And others Happy end drama to add:
Heart to Heart (2015)
High School King of Savvy (2014)
Legendary Witch (2014)
The Man Who Can't Get Married (2009)
Wonderful Days (2014)
One new drama to add: The Family Is Coming (2015)

And Movies Here:
100 Days with Mr. Arrogant
Ai No Kotodama
Ai wa Mieru
Always
Antique Bakery
Baby and I
Bad Girls
Bibou No Diteiru
Boy Meets Boy
Chunhyang
Dating On Earth
Descendants of Hong Gil
Do Re Mi Fa So La Ti Do
Don't Go Breaking My Heart
Finding Mr. Destiny
Fog Street
Formula 17
Hanamizuki
He Was Cool
How to Date an Otaku Girl
How to Keep My Love
I'm a Cyborg, But That's OK (*)
Innocent Steps
Itsuka no kimi e
Joint Security Area
Just Friends?
Kanojo to no Tadashii Asobikata
Kids
Kimi ni Todoke
Love 911
Love In Disguise
Love of South and North
Love On A Diet
Love So Divine
Lovely Complex
My Girlfriend is an Agent
My Little Bride
My Sassy Girl
My Tutor Friend
My Wife Is 18
Petty Romance
Please Teach Me English
Project Makeover
Seducing Mr. Perfect
The Art of Seduction 
The Beast and the Beauty
(that's a big list :D)
New dramas to add:
Love Cells (2014) (*) - Drama Special
Surplus Princess (2014) (*)
The Family Is Coming (2015)
Vampire Flower (2014) - Drama Special
Yellow Boots (2012)
Thank you so much for putting this list together.  I like to avoid sad/tragic/bittersweet endings, so this is very much appreciated!  :)

Here's another one for the list, that has a happy ending: Dr. Gang
The Virtuous Queen of Han, surprisingly, also has a happy ending. :D
Buzzer Beat doesn't have an ambiguous bittersweet ending. It's a happy ending all the way!
I don't see The Girl Who Sees Scents here, so I'm suggesting that one for the list. 2015 drama with a happy ending.
Updated with suggestions. :)   Thanks everyone!   Anything new?
Warm and Cozy (2015). Happy ending!
Ohhh i have some happy ending dramas, but i'm curious, do/will you still update this tread? 

Love me if you dare  (2015 Chinese) You could pick if you would like a happy or sad ending, they show us both endings ^_^
Descendants of the sun (2016)
I remember you (2015)
Kiss me (2015 Thai version of Playful kiss)
Madam Antoine (2016)
Leh Ratree (English name: A women's trickery   (Thai drama) 2015
Ugly ducking series: Perfect match (I think the whole series has happy ending but i don't know) 2015 Thai Drama 

I'll post more happy ending dramas :D