It’s not the most complex game, but Dixit has really beautiful cards, in my opinion.

Not the cards but the money is the Firefly (yes the TV show) board game was very detailed and beautiful.

Parks has very pretty cards (they are by different artists so vary a fair bit)

I picked up Faraway recently and like the art on those cards - slightly surreal fantasy theme.

“Secret Hitler” isn’t beautiful per se, but to me it has a wonderful visual style.

I really like the art style in Unearth. The cards are each different ruins to excavate.

I’m sharing my current favorites here:

• Arkham Horror: Beautiful illustration, as well as a beautiful game in my opinion.
• MtG: Magic cards remain among the most polished and beautiful ever created, even if I hate the direction it has taken, and in general I appreciate competitive games less and less in favor of more collaborative ones; in fact my favorite way to play Magic is with the Archenemy format (there is also an excellent boxed product).
• Marvel Champions: I don’t actually have this in my collection but it looks pretty cool, I have to admit I’m quite a fan of Fantasy Flight Games at the moment!

My favorite is meadow.

https://boardgamegeek.com/image/5949283/meadow

Forest Shuffle is quite educational with its detailed cards and lovely art: https://boardgamegeek.com/boardgame/391163/forest-shuffle

@SolarPunker One recent candidate to this is Abyss. The whole game looks great. #BoardGames

I really like the Ascension art, especially the earliest sets