For me, it was 2004. I was in middle school at the time, just starting to really get into gaming, and MAN, there were so many utterly awesome games released that year, across all genres. Half Life 2 (need i say more?), Far Cry, The Sims 2, Rome: Total War, Unreal Tournament 2004 were among my personal favorites for PC; and for Playstation 2 (OH, the memories ) Grand Theft Auto: San Andreas, Ratchet and Clank: Up Your Arsenal, Gran Turismo 4, Metal Gear Solid 3...lots of very memorable games that left me with many fond memories.

That year really took my interest in gaming to the next level, and it is because of all the fantastic PC games released that year that I really started looking at PC games and the world of PC gaming.

What was the best year for you? What do you think was the best year period?

This year. Black Ops II and Halo 4 a week apart.

2004

Katamari
Halo 2
Dawn of War
Doom 3
Thief Deadly Shadows
Unreal Tournament 2004
Paper Mario
Tales of Symphonia
Rome Total War
Riddike Escape From Butcher Bay
Painkiller
Ratchet & Clank
Sims 2
Ninja Gaiden
Need For Speed Underground 2
Killzone
Jak3
Hitman Contracts
Far Cry
Fable
Battlefield Vietnam
Metal Gear Solid
Burnout 3 Takedown
Ace Combat 3 The unsung war
Pikmin 2
Metal Gear Solid 3
Star Wars Knights of the Old Republic 2
Vampire The Masquerade Bloodlines
Counter-Strike CZ
City of Heroes
World of Warcraft
Everquest 2
Star Wars Battlefront 2
GTA San Andreas
Half Life 2
Counter-Strike Source
Super Mario DS
Pokémon LeafGreen

It's kind of unreal that one year could contain so much gaming greatness, right?

I can't be bothered to look up release dates but I think either 07 or 08 - BioShock and Portal in the former, GTA IV, Fallout 3 and Mirror's Edge in the latter, plus some more I can't remember.

2011 was pretty awesome for indie games. Magicka, Minecraft (sort of), Terraria, Bastion, Space Pirates and Zombies, Trine 2, Dungeons of Dredmor, Orcs Must Die, Spacechem, The Binding of Isaac...

2002 wins for me, mostly for...

The Elder Scrolls III: Morrowind
Medal of Honor: Allied Assault
Grand Theft Auto: Vice City
Medieval: Total War
Delta Force: Task Force Dagger
Gothic II
Mafia
Timesplitters 2
Arx Fatalis

The 90s were pretty great overall, particularly 1999 and 1996.

After 2002... mediocrity.