I've read too many of these for it to be healthy for me, but out of all of them there are absolutely top two: Death is the only ending for a villainess and Stepmother's märchen. Top tier story, art, characters and especially the main heroine. Though going by main characters alone, I'd also include Ruby from HTGMHOMS, she's real.
Generally what makes or breaks an Isekai manhwa is how far the author thinks ahead. If you only think of an interesting premise (The shy duchess starts a tea business) and no actual plot, it'll be only good for like 20 chapters.
And the art!! I prefer unique art that matches the tone, over perhaps more beautiful better shaded art.
And and! A good love interest has interests besides love. I want to feel the world around them, not just the lovey dobrý stuff.
https://www.mangago.zone/read-manga/i_tamed_a_tyrant_and_ran_away/
https://www.mangago.zone/read-manga/failed_to_abandon_the_villain/
https://www.mangago.zone/read-manga/the_villain_discovered_my_identity/
https://www.mangago.zone/read-manga/i_thought_it_was_a_common_isekai_story/
https://www.mangago.zone/read-manga/grand_duke_of_the_north/
https://www.mangago.zone/read-manga/the_villain_s_savior/
https://www.mangago.zone/read-manga/the_beast_tamed_by_the_villainess/
Duke's servant
The one within the villainess
Im so sorry this isnt reincarnation. Idk i was sleepy n suggested that
im a sucker for the overused cold/tyrant emperor or duke falling in love with the mc. i read a lot of them but i dont mind rereading. some of my favs to let you know what i mean:
i became the tyrants secretary, death is the only ending for a villianess, how to win my husband over, divorcing my tyrant husband, being a maid is better than being a princess etc.
some other, different plots i like and woul love to read something similiar:
im a fake saintess but the gods are obsessed with me, the strongest characters in the world are obssesed with me, the villainess stationery store.
(≧∀≦)