I think it's almost an easier question so say what TTRPGs don't have amazing art these days.
Traveller needs a nod, for a game infamous for having minimalist, black-and-white drawings for the longest time, the current edition of full-colour, beautiful, epic imagery is crazy. The art's so good that Mongoose's Instagram page is basically them releasing new images almost every day going, "look what our artists did, isn't this crazy?" And they're usually right. The rulebooks are works of art in themselves.
Free League, obviously. The One Ring needs a shoutout for having very Tolkien-feeling artwork, and Tales from the Loop, though that just straight-up uses Simon Stålenhag's incredible art as its inspiration for everything.
Cyberpunk Red gets kinda forgotten in these discussions (especially if you're tapped out on cyberpunk imagery) but its artwork is really good, and often incredible.
Salvage Union also has incredibly evocative artwork, in a "what if we converted an AT-AT into a mobile home?" kinda way.
Pendragon is also amazing. The core rulebook looks like an illuminated manuscript, but they don't lean so hard on the idea that it becomes unreadable. One of those books you just want to take out and look at to gawp at the art. The Starter Set also rocks in its visual design.