Right now, one of my favorite K pop groups is Exo, especially because they have korean and mandarin! Their songs are so catchy, and they're all so good looking!!!
Right now I'm really into Jason Derulo's song Marry Me. I think that's its just so optimistic and sweet. Such a cute song!
Talking of optimistic songs, Happy is DEFINITELY a good song for being happy. It has a wonderful beat to it, and it just makes you want to bob your head and break out dancing. It's for sure my cheer-me-up song.
I have lot's more songs, but these are just some of my faves as of now!!!