1.It's Okay, That's Love - funny at the same time gives something to think + both leads look good
2.Oh My Venus - funny, easy going story
3.Oh My Ghost - funny & the adventures of a virgin ghostess
4.The Master's Sun - timid girl sticks(literally) to a emotionless man
5.Always - not much talking but the way he expressed his love... SJS movie
6.On The Way To The Airport - mature concept handled maturely, but the romance never dies, it was addictive.
7.High-end Crush - short n sweet
8.Miss Korea - struggle of making the only person (ex-gf who'd work with him) into miss korea, and the sweet romance that starts with it
9.Second to Last Love - love in 40s
10.One Sunny Day - short + SJS
11.You Who Came from the Stars - alien falls for an actress(who is a bit dumb) when he was supposed to go back
12.Sungkyunkwan Scandal - girl studying in boys boarding school disguised that too in joseon era
13.Something About 1 Percent - forced dating, hot tempered guy turns sweet,
14.Goblin - everything except age diff.=the romance, the bromance, the comedy, the thrill, suspense, surprises, the pain, fantasy, the scenery & the OSTs
15.Missing You - starts with a heavy concept of child(young girl) rape, a fine romantic drama that deals with the traumatic memories of the assault
in this priority/order is how i'd do it.