1. Clazziquai- "She Is" and "Be My Love" from Kim Sam Soon OST, and I also like their "Gentle Giant" song from their 3rd album
2. A'ST1- 1.2.3.4 Back
3. Battle- Step by Step
4. BoA (I'm not a fan, but you can try her). Her hits are- NO. 1, Listen to My Heart, Atlantis Princess, Girls on Top, MOTO, Key of Heart, Shine We Are, & Valenti. Actually she has a lot of hits but I can't think of a lot right now lol.
5. Brian (from Fly to the Sky) He released an album called The Brian. All his songs are good

6. Ivy (omg any song from her is great)
7. Se7en (ALL his songs are good)
8. Xing- In Your Hands & My Girl
9. Kangta- Polaris, Pine Tree, and any song really
10. Gummy- I'm Sorry feat. TOP from Big Bang
11. Magolpy- her single Flight Girl
12. Min Kyung Hoon (lead singer from band Buzz. He released a solo album...I like all his songs

)
13. Park Jung Ah (her solo album Vol. 1- Yeah)
14. Jewelry (I personally like all their songs, but their hit is "One More Time")
15. Yangpa (from her 5th album)- Marry Me and La Vie en Rose
16. Ayoomee (Korean singer, not the Japanese ^^)- Her singles Cutie Honey and Wrongful Meeting
17. LEE SEUNG KI <3333333 omg ANYTHING- White Lie, Crazy 4 U, Because You're My Girl
18. KARA- I like their whole first album.
19. Chaeyeon (I'm not a fan but you can try her out)
Hope this helps!