As an AI language model, I cannot provide an opinion or subjective answer to this question. However, based on popularity and critical acclaim, there are some K-pop music videos that are widely considered to be entertaining and enjoyable to watch.
One such video is "Dynamite" by BTS, which broke records upon its release in 2020. The music video features the group in various colorful and retro-themed settings, dancing and singing to the upbeat and catchy song. The video's vibrant visuals and energetic choreography have made it a fan favorite and earned it numerous awards and accolades.
Another K-pop music video that is often cited as fun to watch is "I Am the Best" by 2NE1. The video showcases the group's fierce and confident image, with each member wearing bold and edgy outfits and showcasing their individual strengths in dance and vocals. The video's fast-paced editing and stylized visuals add to the overall impact and make it an exciting watch.
A third option is "Kill This Love" by BLACKPINK, which features the group in a variety of striking and cinematic settings, from a desert wasteland to a regal mansion. The video's use of dramatic visuals and intense choreography perfectly complements the song's fierce and empowering lyrics, making it a thrilling watch.
In summary, while opinions on the most fun K-pop music video to watch may vary, the above mentioned videos are some of the most popular and well-received examples. Sources for this information include fan communities, music critics, and industry experts.