I echo many of these - cuppa, sarnie, rock up, invite as a noun, text as a past-tense verb.
Also second 'shall I make a brew' - I know it's everyday speak in the North, but it just makes me giggle and think that somebody is offering to trump (also hate the word fart) 
May I add wifey, smoosh, zyuzh ('that gives it a little zyuzh' - how do you even spell it?) and preach used as a noun e.g. "That was a cool preach, Rev!"
A precisely defined are/ares (sounds like they're saying arse) when you actually mean our/ours.
This will be very controversial indeed, but buggy instead of pushchair - I absolutely detest it, sounds so very twee, even though it's become a standard word now.
Also, people referring to their iPhone, Range Rover, Louboutins, Rolex etc when there's absolutely no need to specify the brand, other than to show off that you have a particularly expensive variety of phone/car/shoes/watch or whatever.
Supper isn't pretentious at all in large parts of the North and Midlands - you have your dinner around midday, your tea in the evening and, if you want a snack before you go to bed, that's supper.