whats the best bar in newcastle?

Answer 1

I have assumed that you meant Newcastle-upon-Tyne, and not Newcastle-under-Lyme.

As for you question, that's a subjective choice - what's good for you is not necessarily good for someone else. However, here are three websites with listing of pubs and bars + reviews:
1. Knowhere
2. My Newcastle
3. The Burglar's Dog

I hope this is of use.