Can you please suggest me some romance kdrama with happy ending? 

P.S. The male lead actor it has to be handsome. Of course XD

You shouldn't start a thread with titles beginning with "HELP", as it's not a convenient way in a community.

You have watched many dramas so here are some other you might like.

Age of Youth and Dear My Friend (both are amazing dramas) thou are more focused on friendship, family and growing up.
Can You Hear My Heart
Sungkyunkwan Scandal (Don't fret because its a historical one, it doesn't revolve around politics at all)
Nine Times Time Travel
What happened in Bali
A Gentleman's Dignity

There are countless other threads which might help if you just use the search function.
okay I'm sorry. I'm new here. But I ask so many times but there were not reply. Sorry. Thank you for the suggestions, I will check it out.
The Greatest Love, Oh! My Ghost (A bit of murder mystery thrown in there but an excellent drama), Cunning Single Lady, Beautiful Gong Shim (lead actor is so lol), Bride of the Century, Go Ho's Starry Night (its a web drama very cute), Nailshop Paris, She Was Pretty. ^^
Don't worry, this forum is pretty lively. Unless your request for recommendation is difficult, you'll always get an answer within a few hours, sometimes a few minutes.
You can try :
Call of the Country : about undercover agents but it's mainly a romantic comedy
Dal Ja's Spring : noona romantic comedy
Lie to Me : love contract
Ma Boy : gender-bender / school / cohabitation
My Girl : love contract