No salt and vinegar on chips...
I second the no crusts on bread...they're usually like the best bit!
Taking gherkins out of a burger ...
Buying an expensive joint/steak of beef and then cooking it until it is completely brown or slathering it in peppercorn sauce or in any other way disguising the fact that it is good meat rather then sinewy shin purchased for a 'fackin' pahhnd a pahhnd' off some bloke in the pub.
Blimey, pineapple 'sugary-sweet'? It's anything but, in fact pineapple is known for being sharp, unless it's crystallised.
From a personal viewpoint, I'd say putting banana in fruit salad, letting breakfast cereal go soggy, and putting ketchup on anything.
Speaking of overcooking, mum insists on buying the really good Tesco Finest Tenderstem Broccoli (which is lush), and then cooking it until it's practically grey. Utterly pointless and a REAL food crime.
And as for seasoning, I agree seasoning is very important. But I have a gran (who, by the way, has blood pressure through the roof) who, even if something is salted, will put extra salt on herself. I'm talking, she has to add more salt manually regardless of how many people have already salted it.
An example - in Mcdonalds, they already salt the fries (sometimes to death). But mum knows Gran likes extra salt, so got a couple of sachets and put them on for her before bringing the food over to the table. When Gran asked for some salt sachets, mum explained she'd already done it, and without even tasting her (now dead-sea-salty) fries, she said to mum "no, I'll need more salt, hen."
Too much salt... I usually have half a sachet, and Mcd's chips have too much salt when you buy them :|
I hate people who can't use cutlery
Another one I've experienced was just this past Christmas, and it wound me up really badly.
At Christmas, I received a box of Signature Selection Hotel Chocolat chocolates; now, these are pretty damned premium stuff (I think they work out like £1-£1.50 PER CHOCOLATE) so they're very coveted by me... but hey, it's Christmas, right? So I crack open this £25-£30 box of chocolates and offer one to my mum, dad, and sister JUST as my Aunt visits. Clearly I'm not going to pass out chocolates to some people and not others, so my Aunt (who, can I just state for the record, is even more of a total commoner than my immediate family, which says a lot considering our usual meals were special offers from Farmfoods most days) was offered one too. She picked out "whatever one has caramel in it" and took a big bite out of it, grimaced, and said "oh, that's rotten, that one", throwing the remainder away, immediately snatching the opportunity to look at the little chocolate menu and grabbing a different variety, to which she had the same reaction and said "Tommy, what kind of chocolate are they, they taste rancid!"
This alone would've been enough to send me over the edge, but managing to salvage about two thirds of my box from the clutches of the "I'm going to sit here and take a bite out of every one in the box and spit it out like a toddler" brigade, I put the lid back on and put them through onto the kitchen counter. After exchanging gifts, my mum enquired where my young 8-year old cousin was (who had come with my Aunt), and I went through into the kitchen, to see the greedy little pig munching through my chocolates - and I mean, munching. You know in cartoons when you see them not even finishing what's in their mouth before grabbing another? That. With Hotel Chocolat Signature Collection chocolates.
I will never forget the number 8, because it was literally, the number of chocolates remaining in the box I got to keep to myself.