I'd Go with GoldenEye 64 ( for what else the nintendo 64), i'd always play the game until my eyes turned to dust, the game was intensely fun to play with the super awesome Pencil-Like weapon and insanely fast strafing right and left. the game overall was unforgettable

Unreal tournament 1. I've had that game since i was 7.

i'd choose the same, but i didn't discover unreal tournament till 4 years later

Doom (1 and 2). Hands down....

Duke Nukem 3D

im going with shadowblade, doom 1&2 i use to play that everyday with my brother

Yep, Doom 1 & 2..

Then Unreal 1...

Duke Nukem 64! (The slightly modified version of Duke for the Nintendo 64. It had a plasma cannon!)

Yeah I loved that weapon but I got this game very late in comparison to Duke 3D ^^
I would say Unreal 1, but Duke Nukem 3D was the game I truly enjoyed first, too much fun with it, more than doom IMO.
Political incorrectness, great level design, good exploration, the famous taunts (a thing I later loved to have in Tournament), Fun weapons (I mean in doom we have a pretty classic arsenal except the BFG, while in duke we have a shrink gun, a freezethrower, mines in addition to some classic weapons), a huge interactivity (yeah the strip girls, the toilets, all the switches and even the mirrors: Damn I'm looking good)

Quake 2.

Probably Duke Nukem 3D, though thats not saying much considering the only other fps I had access to at the time was a trial version of Rise of the Triad.

Doom is what made those weapons classic

Duke3d is fun, it's cool in Co-op and not serious in the slightest.

But i think Doom still is the game that was most meaningful for me. I prefer Doom 2 to 1 probably though, since i preferred the greater number of enemies and larger open areas

Quake2 however, really got us modding properly. Only several years after Q2 modding did we got into UT99 (2000-2001).

I know doom popularized the FPS, but I think that was that lack of seriousness that was great in duke. Yeah the modding was the best thing that came into gaming.

Well, it all started with Doom 1 (I think, maybe Doom 2), on the Sega Saturn, but that wasn't too heavy. Later I discovered a Demo for Unreal 1 and UT99.

UT99 is where I spent so many hours of my youth on.

Same here.

Though now that I think about it, Quake 2 must have been a solid second place.

I've had Unreal since I was 4, in 1998. You just can't beat it.

UT 99 was great on its own, but the mods added so much fun to it that was practically the game I still play the most.

Good luck running Quake 2 with modern ATi cards and the latest Catalysts. It doesn't run no matter what. At all. ATi really hate legacy OpenGL. The same thing happens with Hexen 2 GL and Quake GL, as well as a good number of older games and OGL-based programs.

Even with a source port like Kmq2 I get as far as the main menu, as soon as the first level needs to be rendered it crashes. In original Q2 I can play in software mode but it crashes if I dare go underwater.

Doom
I was like 24 when it came out. A lot of late nights with that game.

Edit
I was a little off, I was 34 It seemed allot longer than that.
It would appear that it came out in 1993.

Quake had a fair impact on gaming, some of the first games to allow decent modding, first modding experience I had was in quake!, ah crazy campaigns..

After that it was Unreal 1 and of course UT99, many hours of modding on those two...

Ah, those were the days, sorta...

I'm curious to see if I own one of your mods guys

Nah, the first we released was BW for UT2k3

There are others that are not released however, such as some expansive ones for Q2, skins for Q3, UT99 mods and some other stuff

Doom 2! Was obsessed with that thing even though I could only play it at a friend's place. Thats what got me interested in making games even before we knew anything about computers or games.
That was the first game I modded.

Deus ex.

Deus Ex is my favorite game of all times despite some imperfections, it's just genius.
But I was 19 when I got it ^^

Heh heh, after Duke Nukem 64 I was completely stuck on Deus Ex and UT99. Those two games are really the ones that inspired me to start modding. Deus Ex holds the record in my book as favorite game of all time, too.

I started really late, in the middle of high school. So Goldeneye on the N64 came first then all the Half Life stuff (like CS which I never got into.). Unreal was very awesome, and UT99 even more so. U4E mod for UT99 was mad awesome. Twin miniguns, nuclear arrows...those were the days...

Quake 1 Multiplayer, had some real fun, especially with the Weapons of Mass Destruction mod.

My favorites was Unreal,UT and Half Life. Loved Unreal because of the atmosphere, the challenging enemies (The Skarrj sure know how to dodge) and the puzzles. (The Nali water temples where the most challenging IMO.)

Same with Half-Life. the most fun i had was the part where you ride the Black Mesa tramlines to get to the Missile control station. (but i HATED Xen.)
Unreal Tournament had all sorts of neat mods to provide hours of fun while keeping it fresh.