Six at the baltic is good
Cafe 21 is my favorite, although the same guy owns cafe vivo which is less ‘posh’ both on the quayside.
Pan Haggertys gets good reviews, but a bit overpriced, and the portions can be small, again on the quayside.
Jesmond dene house, in jesmond dene (owned by the same guy as cafe 21 and vivo) for really fine dining, big bucks.
curries – sachins is always good, not cheap, a walk from the quayside.
Khans in heaton is quality curry, well priced.
Quite a few pubs do good pub food. the broad chare on the quay is very good (guess who owns it…)
there are others, trip advisor is generally good for newcastle.
EDIT: forgot about Caffe Zonzos in sandyford, really is one of my favorites. Italian, good honest food, great atmosphere.