At the Coast, Sidneys at Tynemouth is good, I had lunch there a couple of weeks ago and enjoyed it. Bay's Bistro in Whitley Bay also used to be good, whilst I've not been for a while I haven't heard anything to suggest it might have changed.
In Heaton/Sandyford, there's a fantastic Italian called Zonzo's on Goldspink Lane in Sandyford. It's a hidden gem which does really good rustic food, especially meat dishes. You can't book but I've never failed to get a table. If you fancy something more traditional/upmarket (not quite nouvelle cuisine but not far off) the Black Door Bistro at the Bisucit Factory is an expensive but fantastic meal.
Getting into Town you have various options...
English - Blackfriars at the end of Stowell St uses ingredients all sourced locally. Cafe 21 behind the Law Courts does similar stuff and has the reputation to boot. Pan Haggerty's on Queen St opened recently is also worth a try if you can manage well sized portions.
Chinese/Japanese - If you want an entertaining meal with good food, Hana-Hana does excellent tapenyaki, but if you want standard Chinese, you can't go far wrong with the King Neptune.
Indian/Thai - I'm not a big fan of curry at lunchtime (strange because I devour it most other times), but if pushed I'd go for Barn Asia behind Dance City - Thai/Asian fusion from the people behind the Barn Again, Barn at the Biscuit and Barn Under a Wandering Star.
Tapas - El Coto on Leazes Lane and El Torero on The Side are owned by the same people and both very good.
The list goes on and on, but these are my favourites. If you've not tried Zonzo's, it's well worth the effort. The wife and I are probably going on Saturday evening if I've recovered from my work night out on Friday (Barn Asia if you're interested).
Perfect timing to get me in the mood for Nigella!
Tim
