Re:Zero kara Hajimeru Isekai Seikatsu, Tensei shitara Slime Datta Ken Recommendations
Both are Isekai anime. If you like this kind of stories, you will like both.
Although re-zero has an slower start, and Tensei Slime has a really quick start, both are really good anime.
If you liked the isekai elements of Re:Zero and were wondering what someone in a similar position as Subaru would do with his knowledge from Earth, Slime is a great show!
Re:Zero and Slime are two sides of the same genre. Re:Zero does a dark and serious isekai to a tee, whereas Slime is the lighthearted power fantasy isekai that isn't so cookie cutter to make you snooze. In the isekai genre these two do it the best.