The other day I was out, and grabbed a burger at a local place. The lady misheard my "abso-fucking-lutly no goddamned pickles or tomatoes." as "extra, extra T&P". The top bun was soaked in neon green pickle piss, and the bottom soggy from the tomatoes splooging out. As a long-time food-service worker, i seldom cause a fuss, or send stuff back, but this was too much. The next try was pretty good, and i was less grumpy.
 
So what ingredients can you not tolerate on a burger (or durger)?  what will make you either not order a burger if its dresed on it, or send it back, besides being too bloody or too burnt?
I think the absolute most disgusting thing I've seen is a british guy put clotted cream on a burger in lieu of cheese.

Feces.

I order everthing i can on my burgers usually...

" Feces. "

Chedder cheese, especially considering how good American is on a burger.

Pretty much anything that isn't mustard, mayo, pickles, cheese, or bacon.

I have to talk to people alot so I can never have onions on my burger and will usually have to tear the thng apart and remove all of it when they mess my order.

Pretty much anything goes for me. However too much shit that makes a mess of the burger is not the way to go.

I can deal with taking off tomatoes from a burger but when pickles enter the mix, I can't do it. Combine those with nasty ol' mustard and you've got a slimy, slide around factor that's just way too much to look past. Not even bacon can get me to eat a pickled, tomato'd, musturd'd up burger.

Onions are pretty bad on my burger of choice... oh and Jalepenos

I don't like bacon on a burger, I know, it's crazy.

I don't like BBQ sauce on a burger...unless I'm at a BBQ

Tofu. 
 
Don't like proper burgers? Don't Eat.

I dont know like slugs..or cockroches probably. Hasnt happened to me yet but Im sure there is a line with hamburgers that I will not cross

I can't stand heavy pickles.

I hate pickles, tomatoes, mustard, raw onions, and mayo on my burgers. When I order, "Only cheese and ketchup" from fast food, because usually lettuce is all soggy and gross.

Any time you can work "pickle piss" into a comment, you have to do it. 
 
I hate burned and/or dry meat more than anything, aside from the obvious (no bugs or other contaminants).

Relish.

" I don't usually have a "dealbreaker" (I like everything), but there is such a thing as too many ingredients at one time.   "

Tomato slices and large chunks of onion are my dealbreakers. Oddly enough, I'm one of the few people I know who doesn't mind pickles on a burger. Thankfully, this means that when I'm out with family and/or the girlfriend, I get everybody else's unwanted gherkins piled into my burger box :)

Mayonnaise.  God help the people who put mayonnaise on my burger.

" Feces. "

usually nothing gets me riled enough to return a burger cause i can usually scrape it off. it's only if they really have messed up my order and basically gave me a different burger then i wanted that i will actually go up and talk to them. Otherwise it's not that big of a deal, just scrape off what i don't want and eat.

" @Mrnitropb: what the hell is clotted cheese ? Can't do pineapples on a burger.  Or avocado.  Just doesn't feel right. "

Clotted cream is a thick yellow cream made by heating unpasteurised cow's milk and then leaving it in shallow pans for several hours. During this time, the cream content rises to the surface and forms clots.  True Cornish clotted cream must be made from unpasteurised milk or the clots will not form. It has a minimum fat content of 55%. Clotted cream is generally served as part of a cream tea on scones with strawberry or raspberry jam.  

" Mayonnaise.  God help the people who put mayonnaise on my burger. "

I like pretty much everything on my burger including the ketchup, mustard, mayo, lettuce, onion, and pickle.  I don't like tomatoes, but if they are accidentally included I can live with it and take them off.  The one absolute dealbreaker for me is if some asshat gives me a hamburger instead of a cheeseburger.  I don't want the burger if it doesn't have the cheese.  Additionally, if you call it a double, it damn well better have at least one slice of cheese for each burger patty.  This new McDouble and Buck Double cost cutting crap with only a single slice of cheese with two patties just doesn't cut it.   
 
I still remember the local burger dump back in my hometown had the best double cheeseburgers:  bun-condiments-cheese-burger-cheese-burger-cheese-bun.  That is right, 3 slices of melted cheesy goodness on a double for only $1.25.  (of course this was circa 1985).

I'm not a huge fan of tomatoes, mushrooms, or avacado on a burger.  That being said, that's not exactly a deal breaker, but I will pick apart the burger to get rid of them.

McDonald's 

Not a relish fan but i'll eat it. Ummm.
Oh yeah Blue Cheese.
Eff that garbage. Blargh

Mushrooms.

Mayonnaise. Only a fucking heathen would soil a perfect berger with that shit. 

Mayo, ranch, mushrooms and blue cheese are huge deal breakers.  I don't care for American Cheese on a hamburger but it ain't a deal breaker.

I will eat just about anything on a burger.  From mushrooms, grilled onions and blue cheese; to all the fixings at a typical backyard BBQ.  I try not to eat at fast food places much though, their version of meat sammich can only loosely be described as a 'burger'.   I'm also probably one of the least picky eaters you're ever likely to meet, just about anything edible is fair game for me, at least once to decide if I don't like it. 

too much sauce , other than i'll eat anything

anything other than beef in my burger

No onions!  Fucking onions...

raw onion, cooked I can deal with. But its not really a deal breaker because I'll just take them off :)

What kind of freak doesn't want pickles or tomatoes?  Die monster!  You don't belong in this world.  

" I order everthing i can on my burgers usually... "

I'm am definitely anti-pickle on my hambogs.  

I don't eat mushrooms or any other kinds of fungus.

Mayo for me.

Finest essence of burger:  
 
half ground sirloin, half lamb 
mayo spread on bun 
fresh ground pepper on mayo 
ripe tomato slice with salt 
 
hoily shit

Maybe it's because I don't really eat tomatoes, but I feel a tomato on a hamburger totally steals all the taste away from the other ingredients. It's too dominant a taste, I think, and it doesn't complement the tastes of any of the other ingredients.  
 
Also: Mayonnaise isn't a dealbreaker, per se, but it kind of makes things weird. Just a weird funk about mayo on a burger. 

Wet bread.

" @Sir_Ragnarok:  I'm completely gay for tomatoes and really can't understand why anybody doesn't like them.  I recognize that many people don't but I do not get it.  "