My Little Happiness - modern romcom, funny and pure fluff among leads when they get together. But ML is smitten with FL from the moment when he finds out who she is (very soon).
Amidst a Snowstorm of Love - story is slow paced, but leads get together fast and it is love at the 1st sight... fluffy and easy to watch.
My Queen - historical (in a game world), since it is arranged marriage, leads are together fast, but their relationship is quite complicated. (ML has hidden identity) Drama is very funny, so it can uplift your mood. It has some sad scenes later, but things are not what they look.
Shanai Marriage Honey - it is japanese drama, but fast paced and extremely fluffy and happy.