Hands down. They've experimented with so many genres, they have done so much in their short career, it's amazing. Truly the kings of 4th gen, and I am so excited to see where they go.
First of all, they have done Runaway, a certified masterpiece. It's dreamy and magical. The song is so catchy with the "bibbity bobbity" bits, and the ending is really nice. It's all about running away, escaping to a new magic world.
They came out last october with the bright, peppy and disco track that is Blue hour! it's so fun, and the dance break is electric! I really really liked this comeback (it officially made me a moa after a summer of halfway there, so go figure) and I think that it's just really cute. Plus, it's super catchy, with all of the "but it's you/you're the one that I want"
A bside perhaps, but Wishlist is really amazing. It's a sweet song, asking what a loved one wants before their birthday comes up, so that they can get them what they want. I especially love the bit at about 1:25 that has Yeonjun singing almost strong all of the sudden, and I just really like it.
So I know that this isn't necessarily their best track, but Nap of a Star is really soothing to me, and I really like the song. The almost breathy way they sing, the softness it's all really nice. It's a go to song for me if I'm feeling sad, or I need to calm down.
Uh, moas please add to this, since I only did 4 tracks. I'll probably add more later too! 
