Name ONE Killer-app per platform...

[level42]

New game: Name ONE absolutely killer-app for a certain platform.
The game must be (for you) the best of that platform. It should drag the most out of it in regards to gameplay, graphics and sound. It should showcase what a platform is capable of if dragged to the far end of its hardware limits.
In fact, that single game should be reason enough to buy the system.

Here comes one important rule: it MUST be a "home" original game, not an arcade conversion. If a game was launched for multiple systems that's OK but no arcade conversions.

I will start with three:

Atari 8 bit: Alley Cat
Atari Lynx: Chip's Challenge
SNES: Super Mario World
PC: Unreal

Of course you can name your killer app for systems already mentioned. NOT more than one game per platform though....

[Blanka]

P2000T: Fraxxon (better than Galaga!)
MacPlus: Beyond Dark Castle
Nokia 3310: Snake
ZX Spectrum: Chuckie Egg 2
Amiga 500: Rick Dangerous 2
Game Gear: Sonic 2 (best sonic of all platforms when it comes to speed and music).

[slowcade]

I really feel that Ruff 'N' Tumble looked far better than what could be expected from the aging Amiga 500. The graphics look amazing, it's difficult to believe that it's an OCS game!
It arrived late in the Amiga's lifespan (1994), and I feel that it didn't receive the recognition that it deserved.

If we're just talking favourite game of the platform, then that's a whole different story.

[joeks]

MSX - Metal Gear
C64 - International Karate +
PS2 - Grand Theft Auto 3
PS3 - Uncharted (can't choose which one)
GAMEBOY - Tetris

[SeTTleR]

Saturn - Sega Rally Championship!!

MSX - Space Manbow

X68000 - Nemesis '90 Kai

We're currently playing Metal Gear for the MSX with a few people together and that game is really hard and sometimes very annoying. There are parts which you simply can't solve without a walkthrough, because you have to find walls that can be destroyed in the whole maze to find needed items, then you enter a truck and it carries you back to the beginning and so on.. quite good game but really really hard and frustrating.

Space Manbow instead really surprised me, because it scrolls smoothly (for an MSX game) and is really a lot of fun to play!

[DarthNuno]

Ok, my selection 

ZX81 : Flight Simulator
Spectrum : Manic Miner
Atari 2600 : Yars' Revenge
CBS Colecovision : gateway to apshai
Amstrad CPC : Who Dares Wins 2
C64 : Impossible Mission
Amiga 500 : Battle Squadron
SNES : Starwing
PSX : FF7
Saturn : Nights
XBOX : Tron 2.0
PS2 : FF10
PC : X-Wing Alliance
XBOX360 : Gears of War

[level42]

Hah, I had listed Yar's Revenge too for the 2600 Bruno but thought you might add it

I agree with Mission Impossible on the C64, definitly pulling a lot out of its graphics and sound. One of the few moments I thought the C64 had the edge over the A8, although there never was a MI on the A8.....

I wonder what I should imagine with a Flight Simulator on a ZX81

I'll add Wings of Death for the Atari ST. Definitly pushed it too it's limits...