Halp

1.moon led journer across another world.
2. ensei Ouji wa Daraketai
3.Isekai Yururi Kikou: Kosodateshinagara Boukensha Shimasu
4.Gaikotsu Kishi-sama Tadaima Isekai e o Dekake-chuu
5.Yondome wa Iyana Shi Zokusei Majutsushi
6.The beginning after the end
7. Yasei no last boss ga arawareta
8.Tensei Shichattayo (iya, gomen)

i can think of these. but believe me there is no novel or manga that is like tensei slime datta ken. its one of a kind. if u want monster reincarnated just follow my list ...theres bunch of reincarnate stories.