This Gen:

1. Super Mario Galaxy
2. MGS4
3. LittleBigPlanet
4. Metroid Prime 3
5. Uncharted

Note: I do not own a 360.

All Time:

1. Ocarina of Time
2. Final Fantasy VI
3. Super Mario Galaxy
4. MGS4
5. Shadow of the Colossus

Damn hard, but i will try..

Current gen @

1. Gears of War 2
2. MGS 4
3. Gears of War
4. Super Mario Galaxy
5. Lost Odyssey

All time.. Jesus gosh, not easy.

1. Metal Gear Solid
2. Final Fantasy IX
3. Shenmue
4. Super Mario Bros 3
5. Gears of War 2

Maybe i should reserve my number 1, until i beat the game.
This gen.
1. Valkyria chronicles.
2. Little big Planet.
3. MGS4
4. Bioshock (xbox 360)
5 .Uncharted Drakes fortune.

All time
1. Chrono Trigger.
2. Metal gear solid 3
3. Final fantasy IX
4. God of war 2
5. SOC

This Gen

1.)Call of Duty 4 - not my favorite but i think it's the best
2.)Metal Gear Solid 4 - Another one that's not my favorite
3.)Zelda Wii
4.)Ratchet PS3
5.)Super Paper Mario

All-time

1.)Super Mario World - SNES greatest game of all-time on the greatest sytem.
2.)Super Mario 64
3.)Pokemon Gold & Silver
4.)Resident Evil 4 Gamecube
5.)Street Fighter II

My Favorite all-time

1.)Super Mario World
2.)Super Mario 64
3.)Sonic Adventure 2: Battle
4.)MS Saga: A New Dawn
5.)Capcom vs SNK 2

honorable mention goes to Megaman Zero 3 on my favorite list.

I didn't include DS game in the current gen list, because I asssume this is for consoles only.

This Gen
1. MGS4
2. LBP
3. Tekken 5 DRO
4. Soul Calibur IV
5. Devil May Cry 4

All Time
1. Final Fantasy VII
2. Final Fantasy Tactics
3. Suikoden II
4. Suikoden I
5. The Legend of Zelda: Ocarina of Time

This gen

Super Mario Galaxy
Super Smash Bros Brawl
LittleBigPlanet
Zelda Twilight Princess
MGS4

All-Time

Zelda Ocarina of Time
Sonic 3 & Knuckles
Roller Coaster Tycoon
Mortal Kombat II
Star Fox 64

This Gen

1. Mass Effect
2. Gears of War 2
3. Crackdown
4. Halo 3
5. Bioshock

All Time

1. Mass Effect
2. Shenmue
3. Starcraft
4. Halo
5. Super Metroid

TOP 5 THIS GEN:

1) MGS4
2) BioShock
3) Gears of War
4) Oblivion
5) Tools of Destruction

TOP 5 OF ALL TIME:

1) MGS4
2) God of War
3) BioShock
4) Gears of War
5) God of War 2

I just have to mention, I feel sorry for it:

6) Ratchet and Clank: Up Your Arsenal.

Note that the lack of games not on Sony consoles is because other than the Gameboy Colour I have never owned a non-Sony console. I have, however, played Gears of War many times and love it.

This
1, Oblivion
2, Fallout3
3, everybody's golf
4, MGS4
5, LBP

All
1, Deus Ex
2, Oblivion
3, Half Life
4, FF VII
5, Dragon Quest VIII

Guess i should say COME ON THE ARSE! (that's the Arsenal in case anyone gets the wrong end of the stick)

This gen:
1) Portal
2) TF2
3) HL2
4) MP3: Corruption
5) Galaxy

All time:
1) Half-Life
2)Tie between Deus Ex and Thief 2: The Metal Age
3) Warcraft 2
4) Diablo II
5) Unreal Tournament 2004

Honorable Mentions:

Commander Keen, Prince of Persia, Starcraft, Smash Bros. (whichever one), Mario Kart (whichever one), World of Wacraft, Golden Sun (and The Lost Age), Metroid Prime, Super Mario, Battle City, Sonic 3, Alien Soldier.