Anything from Leader Games and illustrated by Kyle Ferrin (Root, Oath, Fort...) feels like cheating but still, I absolutely adore their art style
Everdell, Photosynthesis, Parks, look nice as well
I also bought an updated edition of Costa Ruana just because of the illustrations: https://www.pamwishbow.com/client-work/project-four-yjynj-pafyx
When it comes to card art definitely Dixit. When I Dream also has really nice illustrations (and is pretty fun too).
Dixit sure had to be mentioned - when art is effectively your game mechanic it needs to be good. Though it depends on the card set, not a fan of the Dixit Odysey base set