Atari 2600 - Berserk
Intellivision - Pac-Man
Coleco Gemini - (It's a 2600 clone)

Sega Master System - Sonic 2
Sega Genesis/Mega Drive - The Revenge of Shinobi
Sega Saturn - Virtua Fighter 2 (it's my only game )
Sega Dreamcast - Crazy Taxi

Sega GameGear - Sonic 2

NES - Castlevania III: Dracula's Curse
SNES - Super Metroid
Nintendo 64 - Banjo Kazooie
Nintendo Gamecube - Metroid Prime
Wii - Super Mario Galaxy 2
Wii U - Super Mario 3D Worlds

Gameboy - Metroid II: Return of Samus
Gameboy Colour - Pokemon Gold
Gameboy Advance - Pokemon Emerald
Nintendo DS - Castlevania: Dawn of Sorrow
Nintendo 3DS - Pokemon Y

Playstation - Metal Gear Solid
Playstation 2 - Metal Gear Solid 3: Snake Eater
Playstation 3 - Metal Gear Solid 4: Guns of the Patriots

PSP - Metal Gear Solid: Peacewalker
PS Vita - Persona 4: Golden

Xbox - Halo: Combat Evolved
Xbox 360 - Halo 3
Xbox One - Dead Rising 3

PC: Age of Empires 2

Commdore 64 - Giana sisters
Sega Mega Drive - Aladdin
Amiga 500 - Rainbow Islands: The Story of Bubble Bobble 2
Nintendo 64 - Super Mario 64
PS1 - Tekken 3
Xbox 360 - Crackdown
PS3 - GoW 3
PS4 - FIFA 14

Handhelds:

GB - Lion King
DS - Mario Kart DS
Vita - P4 Golden

Update:

recently I have bought SNES

SNES - SMW

In chronological order of me acquiring the consoles

Nintendo GameBoy Advance: Fire Emblem: The Sacred Stones
Nintendo GameCube: Paper Mario: The Thousand-Year Door
Nintendo DSlite: Mario&Luigi: Bowsers Inside Story
Nintendo Wii: Fire Emblem: Radiant Dawn
Sony PlayStation 3: Valkyria Chronicles
Nintendo 3DS: Fire Emblem Awakening
Nintendo Wii U: Lego City Undercover
Nintendo Family Computer: ファイアーエムブレム暗黒竜と光の剣　(Fire Emblem: The Dark Dragon and the Sword of Light)
Nintendo Super Famicom: ファイアーエムブレム　トラキア７７６ (Fire Emblem: Thracia 776)
Sony PlayStation Portable: Valkyria Chronicles 2
Sony PlayStation Vita: Persona 4 Golden
Sony PlayStation: Final Fantasy VIII

I actually own 6 PlayStations, but I guess that doesn't mean I get to choose 6 favourite games, does it? (I don't even own 6 PlayStation games)
I also own a Super Nintendo Entertainment System, but since that basically is a Super Famicom, I didn't include it either. Same goes for my secondary GBA, 2 more or less broken DSlites and my Fire Emblem Speical Edition 3DS XL.

Hard to think of my fav...but I'll go by most played game if I can't think of just a fav

Gameboy/GBA - Pokemon Red/Blue
3DO - Need For Speed
PS1 - Crash series
PS2 - Gran Turismo 3/4
PSP - NFL Street 3
PS3 - Uncharted 1/2
360 - Fallout 3

I've been wanting to get my older cousin's Genesis (I'm pretty sure he has the Sega CD add on as well somewhere) and N64 for a couple years now...They're just sitting in a closet collecting dust. The N64 is practically new since he never really used it that much... He had a SNES too, but my younger cousins have been rough on it from what I year......  I used to play with on the Genesis and SNES a lot when my family visited them.

NES: Super Mario Bros 3
SNES: Super Mario World
Gameboy: Pokemon RBY
Gameboy Color: Pokemon Gold
Playstation: Tony Hawk's Pro Skater 2 (Damn those were the days)
Playstation 2: GTA San Andreas
Xbox: Halo 2 (Runner up: True Crime Streets of LA)
Nintendo DS: Pokemon White
Nintendo 3DS: Pokemon Y
Xbox 360: GTA V (Runner up Dishonored)
Wii U: Super Mario 3D World
PS4: umm... yeah... soon to be... Thief vs Second Son

PS1- Crash Bandicoot 2
PS2- Final Fantasy X/Final Fantasy XII
Xbox- Halo 2
DS Lite- Call of Duty 4 (I only owned this for a few months and it was a Christmas present)
Xbox 360- Lost Odyssey
PS3- Heavy Rain
3DS- Fire Emblem: Awakening
PS Vita- Gravity Rush

Wow. Ok here goes.

1. Commodore 64 : Fave game  = Super Zaxxon

2. Nes : Legend Of Zelda

3. Snes : Donkey Kong Country

4. N64 : Zelda Ocarina Of Time

5. Playstation : Final Fantasy 7

6. Dreamcast : Grandia 2

7. Gamecube : Super Mario Sunshine

8. Playstation 2 : Gran Turismo 3 A Spec

9. Xbox : Halo 2

10. Xbox 360 : Halo 4

11. PS3 : God Of War 3

12. Xbox One : Forza 5

megadrive/ genises - sonic 2
Gamegear - sensible soccer
mega cd - sonic cd
sega saturn - knights
Nintendo 64 - Ocarina of time
Dreamcast - skies of arcadia
PS2 - final fantasy 10
Gamecube - metroid prime
Xbox - ninja gaiden black
Wii - super mario galaxy
Xbox360 - Skyrim
PS3 - Uncharted 2
3DS- a link between worlds
Wii U - super mario 3dworld

1) What gaming systems do you or have you own/owned?
nes : super Mario bros 3

Gameboy : tetris

snes: star fox

n64: zelda ocarina of time

gamecube: super smash bros melee

xbox: halo 2

wii: super Mario bros wii ( I still have 2 games I haven't played xenoblades and metroi trilogy)

xbox 360: halo reach hours and hours

wii u: right now darksiders 2

3ds: pokemon x