On the Japanese side a lot of the famous generals and Daiymos were in Korea for this war, the most famous in terms of martial exploits was probably .
1.Kato Kiyomasa : the nephew of Hideyoshi and one of his most trusted general, he was one of the famed 7 spear of Shizugatake and probably the most active Japanese general for the whole war.
2.Shimazu Yoshihiro was one of the 3 brothers of the Shimazu clan, and the acting daiymo at that time, he was more prominent in the second war.
3.Tachibana Muneshige was a reknown warrior, called the greatest warrior or western Japan by Hideyoshi. he was the lead general that defeated the Ming's first attempt at Seoul in 93.
On the Korean side, aside from Yi Sun Sin obviously being super famous, the other two very famous general in the war was Kwon Yul who led most of the Korean war effort on land after the initial collapse and won a huge victory in 93 by defending a fortress, and probably also Gwak Jae-u who was probably one of the most famous organizer of the militias.
On the Ming front, the two most famous general was probably Li Ru Song, the leader of the first war, and Liu Ting, who particpated in both. Li was the son of the famous general Li Cheng Liang, he had just recently subdued another rebellion before heading strait for Korea, he's known to be a rather reckless general, always putting himself in the heat of danger, in the end he died against a Mongolian raid where he again led a small party to try and take on a far greater host.
Liu Ting's game would grow later on though at that point he was already pretty famous also, he's said to be an exceptional warrior, being able to wield extremely heavy glaives like a light staff even while riding on horsebacks. he specialized in fightin in the mountains of the Chinese South West. so he didn't do much in Korea, but after the war fought several successful campaigns in the south.