Beautiful not just in terms of pixels & resolution *cough Crysis cough COD cough Battlefield, but in an artistic way that makes the game age well together with time.
YuYu Hakusho (SFC)

2D animation based make it looks like watching the show. Still one of the prettiest 2D games out there.


Dragonball Z: Super Saiyan Densetsu (SFC)

Another 2D RPG with emphasis on cartoon like sequences.
Patlabor (SFC)

Most people probably never heard about it. Another game focusing on cartoon like sequences.


King of Fighters 98 (Arcade)

Maybe not as high res as recent releases, it's one of the last true KOF games that retains it's unique art. 99-01 may still retain the drawing style but loses out with their mediocre level designs.


Last Blade 1 & 2 (Arcade)

One of the more underrated titles out there. Yet one of the most beautiful game Neo Geo ever created. The game somehow creates the atmosphere of 2 samurais dueling each other, compared to the Gungho Samurai Spirits, you can say one is fine wine the other german beer.


Metal Slug 1-7

Even up until today, the latest release still looks the same as the 1st title shows how great it looks in 2D sprites.
Lucky And Wild (Arcade)

While not considered artistic. It's quite colorful & fun to watch compared to other aged shooter & driving simulators.
Super Street Fighter 2 X/Turbo (Arcade)

The last true Street Fighter that followed it's original design with much improvements. This game still looks more beautiful compared to Street Fighter IV. Back when 3D & High resolution are overrated. It has the most beautiful Chun Li in the franchise.


Silent Hill 3 (PC)

Over a decade old, this game still has amazing graphics, esp on 1080p. Seems the creators designed it for future hardware. It has one of the most realistic facial expression, done by hand when facial motion tracker weren't common. Still the best looking Silent Hill up to date.


Resident Evil 1 Remake (Gamecube)

Pretty old 3D game but still one of the spookiest & artistic game out there, similar artwork along with RE Zero & Chronicles. Jill still looks great even in low resolution.


Hitman Absolution (PC)

Modern graphic engine & effects with an extra fine touch of art. Every snapshots looks like a concept art more than a 3D game. Something that won't look dated with time.

warning: 1080p

These are what i can think of on top of my head at the moment. As you can see there's only 1 modern games in the list which is Hitman Absolution. Most modern games just emphasize on high res, fancy bloom, realistic view & ignore making their own artistic views, and as a result won't age as well compared to those that do.