#3 Lee Hyun “You Are The Best Of My Life”
This was the single from his first solo EP of the same name. This was a very successful solo release, and along with his work with Homme, 2011 would be a big hit year for him. Here's him doing the song on Sketchbook a few years ago.
#2 Wheesung “Story Of A Cold Heart”
This was his first release after singing on to YMC Entertainment. It was released a few months after revealing that he would be enlisting later in the year. The song was a success, and is still his biggest selling song.
#1 K. Will “My Heart Is Beating”
This was the lead single for his 2nd mini album. The album would peak at #3, and the song would get an all-kill on the charts. It would also give him a few nominations and awards at the year-end shows. The MV stars little bbs Lee Joon and IU.
#5 Song Ji Eun featuring Bang Yongguk “Are You Crazy”
Her official solo debut, and features BAP’s Bang Yongguk. This was a non-album digital release. It is also her biggest selling solo single, and her (and Yongguk’s) first song to peak at the top spot. Here's her solo debut stage.
#10 Girls’ Day “Twinkle Twinkle”
Their first big hit. And still one of my personal favs from them. This is a song from their “Girl's Day Party #3” digital release, and is still the group’s biggest selling song. It was a busy year for them, they would go on to release more songs and an EP. Let's check out their comeback stage at Music Core.
source: KBS WORLD TV, MBCkpop 1 2 3, starshipTV & soompi