For me, 'Daytime Shooting Star' stands out. The characters are well-developed and the romance is heartwarming. Also, the plot is engaging and keeps you hooked.
A really good manhwa romance novel is 'Solo Leveling'. Although it has a lot of action elements, the underlying romance between certain characters adds a great touch. Also, 'Orange Marmalade' is a nice pick. It deals with themes of love and acceptance in a unique vampire - human relationship setting.