Lovely contributions, many thanks!
I think that we all know someone who either mispronounces words or uses the wrong one.
(KatyK I too had a friend who said Panasonic when meaning panoramic, also told me about a fish in Egypt that is so poisonous that if you even touched it's utensils you would be ill, believed in mahogany, and swore that her spare glasses made her look like Dave Haemorrhage !)
And of course little ones words and phrases are often so charming and/or funny!
goose a bit like "Play it again Sam"? 
Right now the things getting "up my goat" are the mis-quoted sayings, I even heard one on Radio 4 today, problem is, I can't remember what it was. I think I might have the beginning of that "Old Timers" disease. (Another favourite of the friend I mentioned)
Of course we could always stray into new territory (a long held Gransnet tradition) of either mixed metaphors or mangled sayings.
One of my personal favourites (and apologies in advance to those who might be offended) is "Does the Pope shit in the woods?"