Fallout 4 - Shit on the game all you want, but the artists that pieced together the world did an amazing job. I have 2500 hours in Fallout 4 and I still find new things hidden in the world when I dig into areas.
Forza Horizon 2, 3 and 4 - Given the map sizes and the speed you travel through it, the attention to detail is amazing in each installment. The coast of France, Australia, and the UK were all packaged into maps that were perfect caricatures of the real locations. They also threw a life-size Hot Wheels track on an archipelago complete with robot dinosaurs. The latest map covers all four seasons with some major changes in each season which is impressive given the size of the map.
Metro Exodus - Going from an icy bombed out city through a desert into forests, this game's world never looked anything but great.
Gears 5 - The stages were much more varied than earlier Gears installments and a lot more opened up. The draw distances and detail were through the roof as well.
Battlefront II - Almost perfectly recreates the look of the films. Planets like Endor and Sullust look incredible.
The Outer Worlds - While the game was a bit lackluster the environments in the game were beautiful and each planet you visited felt unique.
Rage 2 - Very diverse terrain coupled with open world go-anywhere. I often found myself just cruising around looking at shit.
The Witcher 3 - Majestic is a good word for this game's world.
Ori and the Will of the Wisps - This entire game was a monument to the artists involved. It was like playing 60 paintings/second. The environment looked natural despite being made for a game based entirely around some very good platforming.
Titanfall 2 - The game has some very clever environments, one has you flipping back and forth through different timelines instantly. Another has you going through a factory which is assembling a fake town that you fight a boss Titan on.
Games I don't have my own shots of:
Red Dead Redemption 2 - Doesn't really need much of an explanation. Perfect representation of the era it depicts.
Breath of the Wild - While the Switch is no graphical powerhouse, in 300+ hours I never got tired of looking at this world. It seemed so organic in how it was designed, making you stumble across interesting things at every turn.
Xenoblade Chronicles 2 - A world built onto giant living creatures floating in a sea of clouds. The massive differences from area to area kept the game fresh over 300 hours and is among my favorite game worlds.
Xenoblade Chronicles X - The sheer size and scale of the worlds was daunting, and each area was like viewing works done by a new artist. One of the most memorable game worlds I've ever visited.
Super Mario Odyssey - The drastic changes from stage to stage from the odd nighttime Hat world, to a Jungle with a Robot-run plant nursery, to New Donk City, a world made of food, etc. The environments always kept the game moving forward.
There are so many I'm not remembering right now, but my post is already pretty damned long