While true, I would like to point out that games tend to look better in our heads than they do in actual, honest-to-god motion.

Regardless, I do think that the PS2 version of Okami still holds up.

Yep.

Personally, I think the Ratchet games have held up really well on PS2 (particularly the third one).

Anything cel-shaded. Wild ARMs 3 would be my pick, although environments are a little sparse sometimes. Wind Waker would be another contender; as well as Dragon Quest VIII. Cel Damage, to my surprise, still looks pretty good.

And then obviously Vanillaware stuff. Odin Sphere/GrimGrimoire.

Cel shaded games age very well like the original sly games, Jet Set Radio (future), and Wind Waker.

Perhaps for some, but for all the games I listed I'm speaking of recent experience playing them, not vague nostalgic memories.

God damn it.  Videos like that will humble you in a heartbeat.  I was always ready to kill just to get bronze on the dirt tracks.  That was nearly flawless.

But yeah, GT4 still looks good.

I think Final Fantasy IX still looks good, and Suikoden 3 looks awesome.

Stylistically, of course plenty of games still look incredible. But even the best looking games make me cringe when I see all those jaggies. It's the sort of thing that was fine at the time, but looks terrible now that I'm used to HD. (2D games are the exception, as pixel art doesn't work quite the same way.)

For some reason, this isn't really a problem for me. Probably cos I sit a fair distance back  from the TV. (Don't like being too close, it feels cramped)

For example, I've been playing Metroid Prime 2 recently, and I can't ever remember thinking "ugh, those jaggies."

It was actually that game that made me start the thread; two of my friends were over, one of whom mostly plays Battlefield 3 and Dark Souls on PS3, and both remarked at how good Prime 2 looked.

GT4, God of War II and Halo 1 and 2 just to name a few...

Yes, the distance you sit from the TV helps quite a bit. Back at my parent's house I'd sit ten feet from their 26" TV to play my Wii games, and with the exception of Xenoblade (the best Wii game, incidentally), I didn't notice much in the way of jaggies. But in my college dorm, we have a much larger TV and 5-7 feet of veiwing space, so now everything looks awful. :(

Metroid Prime1/2, Wind Waker, Star Fox Adventure, Super Mario Sunshine.