This is probably a bit hard to answer, especially for those who play a bunch of games and don't even remember what they've played a couple of years back.

I have four current favourites myself though:

1. Betrayal at Krondor: This game was simply fantastic when it entered the scene in the early '90's, much due to it's advanced graphics and an interface that was years ahead of it's time. The deciding factor for making this game my all time favourite though, is the incredible story.

2. Half-Life: Possibly the best FPS game ever made when matched up against the era in which it came. At the time, there was simply nothing in the genre that could even come close to the debth this game presented, and its safe to assume that the FPS genre as we know it would've been largely different without this game!

3. Final Fantasy VII: The defining console RPG in many peoples eyes, born in full 3D for the first time on the original Playstation. Visuals and effects were something we'd never seen before, and the depth of both the story and the gameplay blew any game, regardless of genre or platform, away at the time. It's legacy has been one of the most successfull gaming franchises of all time, and all installments of the series are multi-million sellers.

4. Gran Turismo: The king, grandfather and godfather of modern racing games. When it came out, we were playing stuff like need for speed 1 and 2, Top Gear Overdrive and Carmageddon. It was the racing genre's FFVII if you will; presenting debth and gameplay never before seen on any platform. The visuals and the sound was also leaps and bounds ahead of its contemporaries.

I do of course enjoy other games as well, but these are the finest I could muster from my own mind at least!

GT - so many cars so many options.

MGS - Crazy story, i love sneaking around.

Jal&Daxter - just perfect fun.

MGS: Twin Snakes: Damn Amazing, Liquid Snake is the man

RE 4(GC version)= Damn Amazing, addictive, great graphics/sound/enemies

Zelda: OOT+Zelda TP= Damn Amazing- OOT is best game ever..., TP the twilight world sucked me ryt in

Pokemon Red= Damn Amazing (the formulas a bit stale now but back then, I think we can all admit it was the shizzle)... but yeh

Mercs (mega drive/genesis)= OMG! this is so under rated... it was a gr8 top down shooter where you could find, recruit and even increase the power of other mercenaries... great in it's time and great now... I cross my fingers for a VC release

Kotor1 and kotor 2= These were great RPGZ... but with star warss!!! Lol...

Zelda OOT+half-life+WoW

I have a few but of course ill put

FF 7 AND ZELDA ON TOP woot!

FF 7- i was never into rpgs untill i met this incredible game on the playstation, it was the best game i had ever played and i still think to this day is one of the best ever made

Zelda OoT- Fantastic title, the size and experience of the game at the current age was almost unmatched. Its play was fun the story was great and all around one of the best games ever made.


-Honorable mentions
Halo
Other FF games (6, 8 etc)
Mario 64
few others

Fire Emblem - Path of Radiance and Fire Emblem - Goddess of Dawn (yes I can read Japanese a little bit). I don't think I've ever played anything as epic as those two, considering how well they connect to each other and finish the story.

Pokemon Red/Blue + Zelda TP + Zelda Links awakening + Chrono trigger + Final fantasy 6 + Mario bros 3

1) Secret of Mana (SNES) - my first RPG had me engrossed for days !

2) Final Fantasy VII (ps) - The only game i ever felt sad watching and yet so compelling , ah remake please !!

3) Super Mario World (SNES) - ah memories , sleepless nights hunting for those last levels hahaha brill

4) Super Mario Kart (SNES) - Simply Brilliant .

5) Resistance Fall of Man (Ps3) - online is awesome , clocking up more hours than i have since ps1 FFVII .

Honourable mentions go to Tomb Raider(ps) and Resident evil 1+2(ps) just missed out . Oh and buck rogers on the megadrive lol and XCOM on the pc lol enough !!!

edit oops forgot honourable mentions for Zelda OOT and Zelda TP and erm Zelda LTTP

Ocarina Of Time
Final Fantsasy VI
Gran Turismo

All three changed the way I think about gaming.

Tetris is and always will be my favorite game of all time. I can't even begin to tell you how many hours I've spent playing that game in various different incarnations. Thousands, at the very least. It might seem simplistic to many of you, but the challenge of beating that elusive high score always brings me back for more. (That doesn't happen too often anymore, however; my best scores are now in the world-class range, according to Twin Galaxies. I guess that 15 years of practice count for something!)

Other games that have significantly influence me include the original Final Fantasy, the classic Mega Man games for NES and the "X" series for SNES, Goldeneye 007 for N64, and the recent Civilization games (3 and 4) for the PC. My Civ connections have led to actual real-life jobs working for Firaxis Games, and have had a major influence on my life.

Looking at what some others have posted, it seems as though most of you are a bit younger than I am... not that there's anything wrong with that!