After four years and 200 episodes, the creators of "Yoo Hee Yeol's Sketchbook" have seen their fair share of K-pop's top stars.

Yet there was one guest that clearly stood out as the best for host Yoo Hee Yeol--20-year-old singer IU.

"I was really surprised when IU made her first appearance," Yoo said, according to the publication eNEWS.

"I was taken aback at the sight of this little girl singing while playing the guitar."

At a press conference on Wednesday to commemorate the show's 200th episode, Yoo, along with producers Choi Jae Hyung and Moon Sung Hoon and staff writer Lee Yeon, looked back at their favorite guest performers since the show first brought its music-heavy talk show format to the South Korean airways in April of 2009.

For Choi, his favorite performer to grace the "Yoo Hee Yeol's Sketchbook" stage was the duo UV, a joke band who have compared to "Saturday Night Live" alum Andy Samberg's group The Lonely Island.

"I remember UV [the most]," the producer said.

"At first I wondered whether we should allow them on the show, but later I realized they're not people who sing [as a joke], they′re really good at music."

Comprised of comedian Yoo Se Yoon and High Syde's Muzi, UV returned with a new single on Friday called "No Way Can't Be."

The over-the-top music video, which includes antics such as sparks shooting out of Muzi's chest, has already received over 300,000 YouTube views.

Back in May, Yoo Se Yoon shocked fans after turning himself for drunk driving. His license was permanently revoked, according to published reports after police found his blood alcohol level to be past the legal limit.

The incident led to the comedian being fired or suspended from several television shows.

Yoo Hee Yeol also fondly remembered the wacky appearances on his program from singer-songwriter Lucid Fall, at Wednesday's press conference.

"I learned for the first time [through this show] that Lucid Fall has a weird side to him," the host said jokingly. "He′s a psycho."

One moment Yoo said he feels the most proud of from the show was an episode they did about session musicians, which he recalled required some serious planning.

"The session musician special was a special we put together with the utmost care, and we held meetings for it since three months before we were to shoot it," he said.