There are several I can't choose between, so I'll just post my worst for particular consoles that I've played at some point.

N64: Nagano Winter Olympics '98 - The worst one I can remember playing. This one sucked completely
Xbox: Can't decide
PS2: FIFA Street - Absolutely pointless and boring.
Gamecube: Spyro: Enter the Dragonfly - My first Spyro game. Man, one the worst games to be introduced to the series with.
Wii: Telly Addicts - Had family members over and this had been gifted to us by a "friend". So glad I got rid of that. Probably not as bad as the other gift, More Game Party but I didn't play that one.
GBA: David Beckham Soccer - I was 8 at the time and I'm a football fan (Particularly Man Utd). Let's speak no more of this abysmal game
DS: Spyro: Shadow Legacy - My second Spyro game, I've had some bad luck with my choices of entries in the Spyro series. Thank god for New Beginnings and Hero's Tail. Those put things right.
NES: Donkey Kong 3 - Less said, the better
PC: Not going into that, there's too much crap.
SNES: Clayfighter - Played it recently and hated it.
Mega Drive: Sonic 3D Blast - I haven;t played many MD games but i found this quite boring and particularly repetitive.

The worst game I've played is Seablade for the Xbox. Horrible controls that made it unplayable.

NES: Dr. Jekyll and Mr. Hyde (simply unplayable)
SNES: Killer Instinct (boring to learn, impossible to master)
Genesis/Mega Drive: Sonic 3D Blast (This was the first blow of a bad game to Sonic fans, it's a complete insult for it's existence)
N64: Kirby 64 or Wave Race 64 (both of these crapfests are just painful to play)
Dreamcast: Jet Grind Radio (simplifies a bad genre to make it even worse, tossed in with a BS time limit)
PS1: Probably every one of them besides Metal Gear and Strider
PS2: Again, every game besides Metal Gear.
Gamecube: F-Zero GX (Needlessly difficult story mode, bad music compared to the last one) and Rouge Leader: Rouge Squadron 2 (Horrible controls, unplayable)
Xbox/Xbox 360: Every game in their library sucks (if you can actually get the console working in the first place )
PS3: IDK
Wii: Sonic Unleashed (unskipable cutscenes, Bad gameplay and controls on both styles)

Death Valley Rally is Corb's least favorite? I loved it as a kid! I remember I spent one day playing through it, and then playing through it in its entirety a second time, immediately afterward, just to see if there was anything different the second time.

There wasn't.

Not a bad game though!

Rogue Squadron 2 on the GC is unplayable? That was by far my favorite launch game on the Wii and probably my favorite 3rd party Wii game including RE4, Viewtiful Joe, Eternal Darkness, etc. It was a great game.

Anyway, here are my least favorites:

NES - Back to the Future (seriously, picking up clocks?)
SNES - Ultraman (thanks mom for buying this one for me instead of Zelda)
N64 - Superman 64 (I'm the greatest superhero ever, so what should I do? Fly through hoops of course!)
PS - Tomb Raider series (Is that a rock or an enemy? I can't tell because of the crazy pixelated graphics.
PS2 - FFX (Yeah that's right, I said it! I like to play my video games. 2 hours into the game and only 15 minutes of actual gameplay - that's when I turned it off for good)
Xbox - Beyond Good & Evil (I drank the Kool-Aid. It was a waste of money, even if it was only $20)

GBC- Men in Black:The Series
Wii- Probably Super Smash Bros. Brawl

Off the top of my head, it has to be Sonic 3D blast. Extremely Boring.

@Lakitu 64 / @marktheshark
You're both insane.

Worst Wii game for me is currently a toss up between Chicken Shoot and Bob The Builder Festival of Fun. Hmm....
The worst DS game (that I have owned) is Crash Boom Bang! Old school Crash is sorely missed.

I don't know why you would think I just meant the wii anyway, since this is in general discussion, and I don't ever say "what's your least favorite Wii game?" Still, I'm just using games that personally gave me the most frustration because of how badly they were made. Alone in the Dark is one of the only games I've ever sold. I've played a lot of bad games. I've played E.T. and mario is missing, and I still think Alone in the Dark is worse.

nes: clu clu land
snes: vegas stakes
n64: superman64
gamecube: jimmy netron jet fusion
wii POKEMON BATTLE REVOLUTION
ps1 blaster master blasting again ps2 kya
ps3 fear 2
genesis every thing except streets of rage 123
xbox not land of the dead
xbox360 facebreaker

Fanboyism is such an ugly thing.

Alright, thanks for explaining grenworthshero. Dang, the game you mention sounds awful, and I would agree Mario is Missing is not really a worst, compared to other games, though people may have not played certain games or so. :]

And thanks everyone for your fun comments. lol

Sorry, I cannot really mention any least favourite games. Maybe, later on.

Least favorite video game? anything with turn-based or strategy-based gameplay (i'm looking at you, Final Fantasy!)