OP?! Oh! I know two with great story... well, kind of... well... for me at least, I have been following these two a while after the english translation started. They are WN/LN, but I think they have their own manga adaptations too now... I think it was mentioned at some point. Anyways, they are Tensei shitara slime datta ken, about this guy that got killed, became a slime, and built his own country! It has a really good story, the character development and plot twists are great too, actually, I think this one is having its own anime this year, and I can;t wait. The other one is Tsuki Ga Michibiku Isekai Douchuu, it's about this guy whose family had a contract with another world, was then stolen to said other world, then was thrown into the wastelands, then he worked his way up. His luck is on the bad side, and quite extremely so at that. This then creates a lot of interesting turn of events, and right now, I am deeply in love with it. However, the translator is rather new to english, so it might sound off here and there, so you might need to form your own sentences... but it's still a good read!