all games are not created equal

I will always have fond memories of Doom, though my experience started with Doom II (and its super aweome Super Shotgun).  What I remember most was tying up my phone line late at night to death match my cousin.  All that aside,  I always felt single player gameplay in the Doom series was a little too slow and methodical.

 

 Duke Nukem gave me the new experience of frantically running around, using up all my ammo and finally clearing out a room of pigs with my boot to his face, all while being on steroids :)  It was this fast-paced action (as well as some creative weaponry and the Stadium level, which acted as a great 1v1 map for deathmatch) that makes it more memorable for me. 

 

Ahhhh now here's a battle of the old school PC games.  Remember back in the day when you had your 486 or P1s?  Remember when a gig sounded huge?  Well I'm sure you'll remember these to epic games then.  Duke Nukem 3D and Doom ... the founders of FPS everywhere.

Back then these both were amazing, and not to mention all the fun codes that you could enter in to get all their kick arse weapons and god mode.  However, Duke Nukem 3D wins over Doom by a smidge because of the interesting character line and memorable quotes like "kick ass and chew bubblegum" and the dancing strippers which you could get to flash you ... yes that's what makes a game glorious ... besides giant guns, chain saws, and lots of pixelated gore!

This is based solely on the PC versions of both titles.
As much as I try to be biased and say that Doom is the best PC title that I will always cherish til the day I die, I have to admit that Duke Nukem makes for a slightly better game.  It's essentially Doom on steroids (in same cases, literally).
The reason I let Duke slip out in front is cause of the farther exploration of levels.  With the ability to jump, crawl, swim and fly (with jetpack!), there's just more to explore. 
I will give Doom bonus points for monster and texture design though.  Everything in the game looks dark and gritty, almost gothic.  I can remember this being the first game my parents weren't really happy about me playing as a kid.
In terms of shock value though, my parents were even less pleased when I was playing Duke 3d.  You hit up a strip club in the second level!
Comparing weapons is tough because Doom basically laid out the standard types of weapons that would become staples in shooters.  Pistol, shotgun, automatic weapon (chaingun), rocket launcher, higher-damage multipurpose weapon (plasma), then the super rediculous destroy-all weapon (BFG).
I will give Duke 3D for trying hard to come up with a better and unique variety of weaponry.  The shrink ray is sure to raise some eyebrows, and the freeze cannon works well around corners.  Pipe bombs and lazer trip mines were also around before we even heard of Goldeneye for the 64. 
In the end, Doom will always bring back the most nostalgia for me, but Duke Nukem 3D just gave me that bit of variety I needed. 
Come get some!

As stated by many, Duke Nukem seems to have the higher notch in the gaming stick.

I started my gaming on a PC [like most people] and I never went for the old "girlie games" [actually there weren't any :P]. My dad was ALWAYS playing on the PC and eventually got me to try it [attempted with my lil sis too, she doesn't even know where the space bar is!]

I caught on very fast. My father always played either Doom or Starcraft. I started off with SC due to the level of difficulty needed. I passed with flying colours. Then I tried my hand at Doom. Yet again, passed with flying colours, even beating my Dad's high score.

He then bought Duke Nukem 3D. I must admit, I quickly forgot about Doom after that. I thought the grittiness that Duke had gave the game more realistic qualities.

Needless to say, as much as I loved Doom, Duke by far beats its predecessor.