Yes, I am aware that there is a kdrama entitled as Warm & Cozy hehe.

Warm & cozy: hmm.. maybe something that I can really feel the genuineness (realness) of the actors and actress liking each other, since I find most drama as forced and feel so "actingly liking each other".

Sample:

Always (movie)

Coffee Prince

Request: If you will give a list, I hope you pick your top 3 among it / must watch. An explanation on why is appreciated hehe

Some of my favourite dramas that have good acting that doesn't seem forced, also the leads have good chemistry:

High school king of savvy
In time with you
Perseverance, Goo Hae Ra
Sprout

The Master's Sun
Fated To Love You
Good Doctor
The Greatest Love
Bride of The Century
Smile You
Spring Day of My Life ( Sad end )
Fermentation Family
Shan Shan Comes to Eat
My Sunshine
YEY GOOD RECOMMENDATIONS! Thanks!!



Thread still not closed hehe
main leads of Marriage not Dating had really great chemistry however, the drama was sometimes a little bit ridiculous (but still great :))
reply 1997 had in general very nice feel good feeling
It Started With a Kiss & They Kiss Again- The leads had amazing chemistry.
Boss and Me- Pure romantic fluff, my favorite feel good drama. Also My Sunshine is a drama that was adapted by a book from the same author.
Queen In Hyun's Man- so much chemistry here that they ended up dating in real life! I love this drama, I have rewatched it the most :)
Panda and Hedgehog- This is one of my favorite warm and cozy dramas. It makes me feel so happy.
I Need Romance 3- The main male lead is very cute in the romance, though the plot can be a bit frustrating due to the female lead.
Angel Eyes- while the angst can be a little high with this one, all and all it is a warm drama that I enjoyed a lot.
Bride of The Century- also has good chemistry.
Looking Forward to Romance- this is a super short 3 episode drama but it is one of my all time favorites about love. 

I hope you enjoy these dramas :)
It started with a kiss (tai?) - I was not convinced, sorry. this and The Heirs just felt that they were really acting. Compared to Coffee Prince, I Miss You, and Autumn's Tale (old drama). I want to feel that the actors really care for each other, sincerity, or actually 'in love' as cheesy as that may sound. I am quite the person whose particular about good / convincing acting hehe
My top three romance fuzzy feel dramas(in no order) - 

Secret Garden - Boy it was a roller coaster but ultimately there acting was spot on and made you really feel like they were in love (the i'd do anything for you type of feel). Had me in tear and laughter throughout. Deffo a must watch. Hyun bin is so handsome in this too

Lovers - An older one in the mix for you. Romance takes a while to get going through all the ups and downs. Different genre to the above where-as he is a gangster and she falls in love with him. Totally real feel and i believe they do actually become a couple due to this drama (now broken up). He's not too bad looking either ;-)

The master's sun - Again a different type of romance in that the main female believes she cannot live without the main man. Main man is a total pr!ck and cold hearted though so can imagine how hard it is for her to connect with him. The start of the romance look a bit 'forced' but towards the end it really does look like true love.

All K-dramas though - hope that ok. All worth a mention. I'm a 28 year old female who loves a good romance so i think you and your friends should like the above.

An honourable mention and something a bit different (as it's a longer family drama) but one of my all time favs is Smile, You. Only didn't mention it in the above as it's longer in episodes and doesn't suit everyone. If you have the time, do watch it. It's funny, heart warming and gives you a sense on family.

Not a huge fan of Taiwanese drama's but ones i did enjoy are - Devil beside you, Drunken to love you, just you and easy fortune happy life.

Enjoy
Coffee Prince like feels? hmmm..

Boss & Me (pure fluffy romance)
Smile, You (even though it's long, the couple's so natural and cute together)
ISWAK & TKA
In Time With You (wonderful lead characters and chemistry)