I'd have to give past consoles some thought, but it looks to me like GTAV will squeeze every last bit of juice out of our current systems.

The Galaxy games, GTA V, Dragon Quest IX, Resident Evil Revelations and Spyro: Year of the Dragon are some of the best for me.

Crysis on pc. Still as good or better looking than any console game but released in 2007

Donkey Kong Country SNES

SNES: Donkey Kong Country 1 & 2
N64: Perfect Dark and Conker's Bad Fur Day
PS2: Metal Gear Solid 3
GC: Rogue Squadron III (a damn shame Factor 5 killed themselves with just one PS3 launch game, they made the best Star Wars vehicle/star ship shooters) and Legend of Zelda: Wind Waker (best cel shading art style in a non license game until Ni No Kuni on PS3).
Xbox: Chronicles of Riddick
Xbox 360: Halo 4 and Tomb Raider
PS3: The Last of Us, Ni No Kuni and Journey
Wii: Legend of Zelda: Skyward Sword and Super Mario Galaxy 1 & 2

pitfall atari 2600

N64 Turok 2 Seeds of Evil,

GC Metroid Prime ,StarFox Advenures,SW Squadrom II and III

ahead of its time

Donkey Kong Country

Metroid Prime 2 pushed the gamecube more than the first one.

I'm not really a "graphics" person, but there have been a few that just blew me away.

Final Fantasy VII on the PS1 was like a bombshell compared to the pea-shooter that was my SNES. It was a real jaw-dropping, holy cats moment.

Speaking of jaw-dropping, I still remember sitting there in total awe when I first popped Gran Turismo 4 into my PS2. I'm being serious, too, I can remember it clearly. It was simply majestic. For the first time with a videogame, it felt closer to being real than to being pixels.  That GT40 still gives me the damn chills.  Bloody epic.