Possibly a controversial take, but I feel like the Gamecube has weirdly aged better than the Xbox.

Xbox was more powerful, and games like Chronicles of Riddick, Doom 3, and Halo 2 were seriously impressive at the time, but in retrospect I feel like their early use of pixel shaders hasn't aged as gracefully as Gamecube's best looking titles.

Aside from the ones listed before, I feel that RE4 has aged incredibly well for a "realistic"-style game. They did a phenomenal job on the OG on the GameCube.

Amen, holds up way better than it has any right to as a game attempting realism on now 25-year-old hardware.

Not to diminish achievement of GC version, but I think those gifs look like they are from Resident Evil 4 HD Project, which is mod for PC's RE4 Ultimate HD Edition from 2014.

Warning: Loud background music in video

Perhaps not a fair comparison, because I emulate and use upscalers, but GoW and GoW2 have aged amazing. Still look and play top notch.

Those are definitely two of the very best looking games on PS2, along with the likes of RE4, Black, and Shadow of the Colossus. On real hardware they do have variable performance and screen tearing as I recall, but they do hold up remarkably given the age of the hardware.

I am still blown away by emulation.  Upscaling and a few texture packs and old games look/perform quite well.  I got a good texture pack for Mario 64 with 4x upscaling, looks good.

What is curious is the only game I cant emulate worth a crap is Rogue Leader.  Apparently it uses a bunch GC specific systems and emulation is a nightmare.  

Yeah Factor 5 who made the Rogue Squadron games were insane technical wizards that came up with the craziest custom code tricks to really max out the hardware; it made their games some of the absolute best looking GC/N64 titles, but also means they're a bitch to emulate.