My favorites are probably the 10.8/10.9 rounded flat matte w/perspective look because it does such a nice job of looking polished without being garish (unlike the 10.5-10.7 glossy dock, which I didn't like that much) followed by the 10.2-10.4 for its sheer simplicity. 10.1/10.2 gets third place simply because they're the OGs and the pinstripe texture was fun.

10.10 onwards is pretty forgettable.

During the 10.5-10.7 era there were a number of third-party dock themes people made that worked by swapping a few image resources, which in addition to visuals could adjust reflectiveness. I had mine set to a nice studio-lit dark gray matte shelf with white 3D indicator arrows.

There was some discussion about the Finder icon in a previous thread a while back. It's a riff on the original 'Happy Mac' power-on-self-test icon. My take is it's based on the reflection of the user's face against the monitor, reflecting enjoyable human-computer interactions. Also you get a smilely face on your screen.

This icon goes back to the Mac Clone era when they wanted separate branding for System 7.5 etc. Kinda funny it survived Jobs and is still around.

Also, IMO there's a lot of undue nostalgia for Snow Leopard. But that 3D Dock was cool. (It didn't do that when you put your dock where it belongs, on the right side.)

The last Mac I used before buying a Neo was a PowerMac G5 running Leopard. So it's probably just due to familiarity/nostalgia but I think it was the best OS aesthetic out of everything I've used.

I miss the 10.10 - 10.15 era

[delayed]