Burglars Dog sums them up perfectly...
"While I'm on the subject of regional stereotypes, people often ask why Newcastle and Sunderland hate each other. The simple answer is we don't: they hate us, but we just find them amusing. Have you ever witnessed such an embarrassing display of inferiority complex? We have a world-famous bridge; they get themselves a crappy fun-size version of it. We're a famous city - with the mandatory cathedral - so they mewl and whine their way to city status, whether they're entitled to it or not. Just the fact that it's Tyne and Wear and not the other way round is enough to turn them apoplectic, the poor, downtrodden, vowel-mangling oafs. And - despite the fact that we're geographically north of Wearside, you'll never hear of a mackem going UP to Newcastle - always 'through'. Or is that thrayeew? There is, however, one thing that Sunderland trumps Newcastle on, and that's the Air Show. People from Newcastle go to the airport to see planes up close, and maybe even board them to destinations near and far. Sunderland inhabitants, meanwhile, gather on beaches and in fields to marvel at the displays above them. 'Lewk, Jewley! A big metal bird flying over thee 'ouse!' Fucking airshow. Only in Sunderland… "