I finally found the time to read the entire list. Unfortunately, ignorance seems to be widely spread. 
1. When people ask for something, I often hear: "Can I get a..." It infuriates me. It's not New York. It's not the 90s. You're not in Central Perk with the rest of the Friends. Really." Steve, Rossendale, Lancashire
It's "Central Park", not "perk". Also: "friends", not "Friends". It helps to master your own language before you criticize foreign ones.
2. The next time someone tells you something is the "least worst option", tell them that their most best option is learning grammar. Mike Ayres, Bodmin, Cornwall
Amazing. I googled it and found this gem mostly on UK websites. Americanism is the new synonym for bad grammar? 
3. The phrase I've watched seep into the language (especially with broadcasters) is "two-time" and "three-time". Have the words double, triple etc, been totally lost? Grammatically it makes no sense, and is even worse when spoken. My pulse rises every time I hear or see it. Which is not healthy as it's almost every day now. Argh! D Rochelle, Bath
As explained in a previous post. Please expand your vocabulary.
4. Using 24/7 rather than "24 hours, 7 days a week" or even just plain "all day, every day". Simon Ball, Worcester
Wrong. 24 hours means all day AND all night.
5. The one I can't stand is "deplane", meaning to disembark an aircraft, used in the phrase "you will be able to deplane momentarily". TykeIntheHague, Den Haag, Holland
Aviation industry is a bizarre world.
6. To "wait on" instead of "wait for" when you're not a waiter - once read a friend's comment about being in a station waiting on a train. For him, the train had yet to arrive - I would have thought rather that it had got stuck at the station with the friend on board. T Balinski, Raglan, New Zealand
Please learn English. "To wait on" and "to wait for" are entirely different things.
7. "It is what it is". Pity us. Michael Knapp, Chicago, US
As far as I know, this is a quote from some piece of literature.
8. Dare I even mention the fanny pack? Lisa, Red Deer, Canada
Honi soit qui mal y pense...
9. "Touch base" - it makes me cringe no end. Chris, UK
Sports lingo, so what?
10. Is "physicality" a real word? Curtis, US
Yes, ask Webster's.
11. Transportation. What's wrong with transport? Greg Porter, Hercules, CA, US
Because transport and transportation are two different things.
12. The word I hate to hear is "leverage". Pronounced lev-er-ig rather than lee-ver -ig. It seems to pop up in all aspects of work. And its meaning seems to have changed to "value added". Gareth Wilkins, Leicester
Interesting pronunciation. 
13. Does nobody celebrate a birthday anymore, must we all "turn" 12 or 21 or 40? Even the Duke of Edinburgh was universally described as "turning" 90 last month. When did this begin? I quite like the phrase in itself, but it seems to have obliterated all other ways of speaking about birthdays. Michael McAndrew, Swindon
Because not every birthday comes with a party and a clown? Other languages distinguish as well.
14. I caught myself saying "shopping cart" instead of shopping trolley today and was thoroughly disgusted with myself. I've never lived nor been to the US either. Graham Nicholson, Glasgow

15. What kind of word is "gotten"? It makes me shudder. Julie Marrs, Warrington
Old English.
16. "I'm good" for "I'm well". That'll do for a start. Mike, Bridgend, Wales
Two different meanings.
17. "Bangs" for a fringe of the hair. Philip Hall, Nottingham
I am wondering what this gentleman would think about Germans then. They call it a Pony.
18. Take-out rather than takeaway! Simon Ball, Worcester
"Take away". Aren't you going to pay for it? Shocking. 
19. I enjoy Americanisms. I suspect even some Americans use them in a tongue-in-cheek manner? "That statement was the height of ridiculosity". Bob, Edinburgh
Tongue-in-cheek, indeed.
20. "A half hour" instead of "half an hour". EJB, Devon
Because "a half hour ride" is not the same as "arriving in half an hour".
21. A "heads up". For example, as in a business meeting. Lets do a "heads up" on this issue. I have never been sure of the meaning. R Haworth, Marlborough
Look it up?
22. Train station. My teeth are on edge every time I hear it. Who started it? Have they been punished? Chris Capewell, Queens Park, London
Because it's the trains that stop at the station. Not the railway. This would be unfortunate.
23. To put a list into alphabetical order is to "alphabetize it" - horrid! Chris Fackrell, York
Especially British , al·pha·bet·ise .
Origin:
1865–70; alphabet + -ize
People that say "my bad" after a mistake. I don't know how anything could be as annoying or lazy as that. Simon Williamson, Lymington, Hampshire
A play on words. Native speakers should be able to figure it out.
25. "Normalcy" instead of "normality" really irritates me. Tom Gabbutt, Huddersfield
Normalcy is not interchangeable with normality in some contexts. For example, in comparing an untypical condition to a typical condition, one would want to pair abnormality with normality and not normalcy. Although the form “abnormalcy” is showing up on the web and even in some dictionaries, it’s not in the OED, and it is not standard in American speech.
26. As an expat living in New Orleans, it is a very long list but "burglarize" is currently the word that I most dislike. Simon, New Orleans
Well, In England it's called "burglarise".
27. "Oftentimes" just makes me shiver with annoyance. Fortunately I've not noticed it over here yet. John, London
Old English term, extended form of often, attested from early 15th century.
28. Eaterie. To use a prevalent phrase, oh my gaad! Alastair, Maidstone (now in Athens, Ohio)
"restaurant," 1901; see eat + -ery. It's "oh my gawd", not "oh my gaad".
29. I'm a Brit living in New York. The one that always gets me is the American need to use the word bi-weekly when fortnightly would suffice just fine. Ami Grewal, New York
Yikes. Those are two different meanings! I hope he made his appointment.
30. I hate "alternate" for "alternative". I don't like this as they are two distinct words, both have distinct meanings and it's useful to have both. Using alternate for alternative deprives us of a word. Catherine, London
No, you cannot interchange a verb with an adjective. Smart girl!
31. "Hike" a price. Does that mean people who do that are hikers? No, hikers are ramblers! M Holloway, Accrington
No. But you should learn a bit about negotiating.
32. Going forward? If I do I shall collide with my keyboard. Ric Allen, Matlock
You should leave your house more often and spend some time at the office.
33. I hate the word "deliverable". Used by management consultants for something that they will "deliver" instead of a report. Joseph Wall, Newark-on-Trent, Nottinghamshire
Because not every deliverable is a report, Einstein.
34. The most annoying Americanism is "a million and a half" when it is clearly one and a half million! A million and a half is 1,000,000.5 where one and a half million is 1,500,000. Gordon Brown, Coventry
Gordon Brown needs new glasses.
35. "Reach out to" when the correct word is "ask". For example: "I will reach out to Kevin and let you know if that timing is convenient". Reach out? Is Kevin stuck in quicksand? Is he teetering on the edge of a cliff? Can't we just ask him? Nerina, London
Two different meanings.
36. Surely the most irritating is: "You do the Math." Math? It's MATHS. Michael Zealey, London
British preference, maths, is attested from 1911. Hm. Looks like the plural was invented by the British not too long ago.
37. I hate the fact I now have to order a "regular Americano". What ever happened to a medium sized coffee? Marcus Edwards, Hurst Green
Where did this man order his coffee? Most definitely not in the US.
38. My worst horror is expiration, as in "expiration date". Whatever happened to expiry? Christina Vakomies, London
Let's all hope that Christina will not expire sometimes soon.
expiry Look up expiry at Dictionary.com
"close, termination," 1752, from expire + -y (1). Meaning "dying, death" is from 1790.
expiration Look up expiration at Dictionary.com
early 15c., "vapor, breath," from M.Fr. expiration, from L. expirationem/exspirationem (nom. expiratio/exspiratio), noun of action from pp. stem of expirare/exspirare (see expire). Meaning "termination, end, close" is from 1560s.
39. My favourite one was where Americans claimed their family were "Scotch-Irish". This of course it totally inaccurate, as even if it were possible, it would be "Scots" not "Scotch", which as I pointed out is a drink. James, Somerset
Sorry, James. They said "Scottish", not "Scotch". Were you thirsty? 
40.I am increasingly hearing the phrase "that'll learn you" - when the English (and more correct) version was always "that'll teach you". What a ridiculous phrase! Tabitha, London
I never heard that one in the US.
41. I really hate the phrase: "Where's it at?" This is not more efficient or informative than "where is it?" It just sounds grotesque and is immensely irritating. Adam, London
Dear Adam, whenever you inquire about the status of a project or a process, you might be not very interested in its geographical position, right?
42. Period instead of full stop. Stuart Oliver, Sunderland
Why not? Means "dot marking end of a sentence", first recorded c.1600.
43. My pet hate is "winningest", used in the context "Michael Schumacher is the winningest driver of all time". I can feel the rage rising even using it here. Gayle, Nottingham
A typo? In the US a student would get an F. Did you read this on MySpace?
44. My brother now uses the term "season" for a TV series. Hideous. D Henderson, Edinburgh
Those terms are not interchangeable. A TV series might run for ten years but the episodes during a particular year are called a season.
45. Having an "issue" instead of a "problem". John, Leicester
Because not every issue is a problem? Get happy!
46. I hear more and more people pronouncing the letter Z as "zee". Not happy about it! Ross, London
Bee hives nearby? (Sorry...
)
47. To "medal" instead of to win a medal. Sets my teeth on edge with a vengeance. Helen, Martock, Somerset
Sportscaster lingo.
48. "I got it for free" is a pet hate. You got it "free" not "for free". You don't get something cheap and say you got it "for cheap" do you? Mark Jones, Plymouth
Teenager lingo. So what? Perhaps British teenagers go strictly by the Oxford Dictionary.
49. "Turn that off already". Oh dear. Darren, Munich
I am certain that all parents all over the world are watching their grammar when asking their kids to reduce the volume of their latest Black Metal album from supersonic to the modest hum of a jack-hammer.
50. "I could care less" instead of "I couldn't care less" has to be the worst. Opposite meaning of what they're trying to say. Jonathan, Birmingham
Good catch, Jonathan! "Could care less" is wrong. You won't hear this gem by a US native speaker.