It could be visually beautiful, mechanically or otherwise.

I’m a visual person, so I have to go with Photosynthesis. It has an amazing table presence and the artwork is amazing. Seeing the trees slowly fill the clearing and, if the lighting is right, cast their shadows is very special.

What's your most beautiful game?

@tabletopgamesblog tough question as there are so many! Squishy berries in Everdell definitely give it a bump. My eyes darted up to the Lacerda corner of the Kallax and landed on Lisboa which I think is a joy to look at. My wife chimed in with Feudum from 7/8ths asleep which is impressive and a solid choice, too.
@qeek Everdell certainly has an amazing table presence. I'm not surprised so many people mentioned it. I never played Feudum. but from the photos of it I've found, it does look pretty cool.