can't make a poll so here are your options.
 
Banjo-Kazooie
Borderlands
Dead Rising
Duke Nukem 3D
Splinter Cell: Conviction   
Heavy Rain
EDIT: Goldeneye
EDIT: No More Heroes - (Even though they stole it from Dead Rising.)
EDIT: The Sims

Portal. I know I'm not the only one that was having a blast cramming stuff into the toilet in that first room. 
 
I gotta show some love to Goldeneye here too, because that bathroom in the Facility was just too awesome.

Your list is invalid and incomplete without No More Heroes and its sequel.

The Sims, cuz if they did not exist my sims would piss themselves constantly.

Hmm, i choose none of the above and raise you one Goldeneye on N64 and No more heroes on the Wii.  The last one may only be a way of saving but it makes me chuckle every time i see it.

No More Heroes

" The Sims, cuz if they did not exist my sims would piss themselves constantly. "

Throwing FFXIII in the toilet. 
 
Ba dum tsh.

No More Heroes, but I did quite like the peeing in Heavy Rain.

Half life 2 has an achievement to kill someone with a toilet, so that gets my vote.

" @TheSeductiveMoose said:

" The Sims, cuz if they did not exist my sims would piss themselves constantly. "

FUCK THE SIMS AND THEIR TOILET OBSESSIONS.  I LET MY SIMS PISS THEMSELVES. "

" @InfamousBIG said:

" @TheSeductiveMoose said:

" The Sims, cuz if they did not exist my sims would piss themselves constantly. "

FUCK THE SIMS AND THEIR TOILET OBSESSIONS.  I LET MY SIMS PISS THEMSELVES. "

I HAVE A SAMUEL L JACKSON SIM, IT WOULD NOT BE RIGHT TO LET HIM PISS HIMSELF. "

The Chronicles of Riddick: Escape from Butcher Bay had some pretty good toilets, but I'd have to say No More Heroes (the first one more than the second one) is the real winner. Having your dude sitting on the toilet with the game's logo graffiti'd on the wall behind him, with a different graffiti-font and toilet depending on where you have saved last? Fucking brilliant. And no, NHM did not "steal" that from Dead Rising.

" Half life 2 has an achievement to kill someone with a toilet, so that gets my vote. "

i liked splinter cell convictions use of urinal 

Doom 1 & 2 when people made their own toilets.  When seeing a toilet in a game was like "OH SHIT I KNOW WHAT THAT IS SUPPOSED TO BE!"

" Crackdown 2 has the biggest toilet I have ever seen "

Although I don't usually approve of retarded quest threads, this one is not complete without the chron-o-john.
 

This poll is invalid as it doesn't take into account Half Life 2 : Deathmatch.  Gravity Gunned Toilet Projectiles are the best use of toilets in a video game.  EVER.

" Fallout 3, yummy. "

Resident Evil 5 does note 'nothing of use here' when inspecting a toilet.

You all suck for not mentioning Boogerman

Portal. I know I'm not the only one that was having a blast cramming stuff into the toilet in that first room.   I gotta show some love to Goldeneye here too, because that bathroom in the Facility was just too awesome.