I can't see Bruno's site and I assume it's because of the HN hug of death, but an impressive 3D website that always comes to mind is acko.net, with its 3D rendered tubular logo. He even describes how it was done in a blog post.

https://acko.net/blog/zero-to-sixty-in-one-second/

acko.net is one I thought of immediately too. The front page for Three.js usually has some nice examples too.

Of course, with WebGL and WebGPU support becoming ever more ubiquitous I'm not sure when 'impressive 3D website' just becomes either 'impressive website' or 'impressive 3D'.

[1] https://threejs.org/