I'm a fan of the 2nd revision myself, it's sooo Web 2.0

https://seeklogo.com/vector-logo/492036/linux-tux

But the OG Tux remains undefeated I'm afraid

That's the one (besides OG Tux) I liked most. Though the "glassy" original Tux wasn't bad at all.

https://seeklogo.com/vector-logo/274040/tux

Testament to it's appeal is when it's used by businesses to promote their ice creams/slushies.

There were times when Crystal was even "ported" as Windows visual theme and later as package that swapped resource files: https://archive.org/details/crystal-xp-3.0

Wow what a flashback! I think I used to use this back in the day.

I had tons of these "visual styles" and I remember how MS liked to patch themeui.dll and uxtheme.dll often rendering theming broken.

There were also attempts at customizing XP booting screen to achieve the perfect "it's not Windows" effect but that could easily render installation unbootable

That... Brings back memories

Stroke Tux

Clearly modules were broken and kernel couldn't be build