I thought that Newcastle was a boring town
It has a great nightlife - the pubs vary from moden, smart, even trendy places to quite old places where people play live folk music (not badly like in many places - these people believe in it - see Cumberland Arms). There are of course the noisy places (see Big Market). There is a jazz club that I highly recommend.
The shopping is good if you like that sort of thing. Indoor markets, all the big shops, small independent shops. Check out Central Arcade. Never miss out on a Sunday trip to Tynemouth with its market in the station.
The Metro makes travel around the place easy. The Baltic centre exhibits all kinds of amazing artwork. I've forgotten the name, but there's a much smaller gallery well worth a visit. The architecture is great - the prototype of Syndey harbour bridge, some of the modern buildings, churches (especially All-Saints). The two universities ensure an interesting mix of people. I like the Geordies. Not all of them but...
edit: I didn't even mention it is the home of Viz.