Hello!
can you recommend me good Taiwanese / Chinese / Japanese RomCom or melo dramas?
i have already watched..
Autumns concerto
just you
ouran high school host club
atashinchi no danshi
Boss & me (shan shan comes to eat)
le jun kai
love me if you dare
devil beside you
sealed with a kiss
meteor shower
fall in love with you
On the wings of love(Ph)
These are all Taiwanese Rom Coms:

Fated To Love You- There is a Korean remake of this, but I don't know how much of it is the same as the original Taiwanese version.
Drunken To Love You
Down With Love
It Started With A Kiss
Skip Beat!- There are two Korean actors in this that are dubbed, I know some people can't stand dubbing, but I really like this drama.
Sunny Happiness


Thank you @squeakyelle 
pleasently surprised
me too flower
Dandelion Love, Say That You Love Me, Last Cinderella, Hana Kimi Taiwan, Hana Kimi Remake, Hana Yori Dango, Long Love Letter, Mother, Absolute Boyfriend, Easy Fortune Happy Life
thank you @amitspiky @CherryBunny 
See also the Taiwanese drama Just You It's a very beautiful
taiwanese drama :
* in time with you -- there is korean version but i like this version better
* mars -- now also jdrama version airing 
chinese drama :  
* divorce lawyer -- this is my 2nd fav chinese drama after shan shan -- very funny but also romantic 
thanks @NWCDH @Siane 
Love Shuffle
Nobunaga Concerto
1 Litre of Tears
Taiwanese drama - In Time With You!! The best! <3
I really like Perfect Couple, Cruel Romance, and The Lady and the Liar
thank you @Tara @beatriz @Millian
Many people already recommended some that I would write on the list so I'll just add to it. 

Taiwanese:
- Calling for love
- Smiling Pasta
- Prince turns into frog
- My lucky star
- Love keeps going

Chinese (modern romcom):
- Love through a millennium (this is the chinese remake of queen inhyun's man, its timetravel)
- waking up love
- Queen of SOP
- The whirlwind girl
(historical/melo)
-  Rapture and found (the only historical romcom on my list)
- the journey of flower
- prince of lanling
I don't know if you watch historical political intrigue but I have one that's a absolute must watch and a few really good ones
(historical/political)
- Nirvana in Fire
- Scarlet heart
- Virtuous queen of han

Japanese romcom:
- Itazura na kiss; love in tokyo 1+2 (there are taiwanese, korean versions but this version is my fav)
Melos: Taiwanese - Summer's Desire
             Japanese - Siren (crime)


Rom Com: Taiwanese - Hello My Sweetheart
                   Japanese - Last Cinderella

**Honorable mention for Palace: The Lock Heart Jade (it's like the cheesy version of Scarlet Heart ;-)**