I usually just ask my wife and she does research on the internets for me.
She is quite good, finds them through articles in the local papers mainly. I cant remember the last time I looked at Zagats. I have zero confidence in them. Likewise, in NY, now that whats his name is the food critic, I look for places he hates as likely standouts. Concierges are often a very good source as well.
Also - dont forget FT! I have found some great places, in HEL for instance, but in many other cities as well due to my FT colleagues.