Blackfish is probably the best birthday dinner in Lincoln City. At the less fancy end of the scale, Andaman Thai might well have the best food in town. If your wallet is too heavy, the Bay House does the kind of fine work commensurate with their prices.
Down in Newport, I hear very good things about Saffron Salmon. If you're looking for heartier food, Nana's makes some of the best pot pies around. I've never seen anyone leave there hungry or in a bad mood.
If it helps, my wife tends to insist on Andaman, Blackfish or Nana's for celebratory dinners.
I can't bring myself to recommend the the casino for food, and that joint definitely has negative ambience. If you go, you absolutely don't want to order the ambience. As for Fathoms, I'd suggest that it's best to pretend that it doesn't exist. That may be my problem, but the food and the decor remind me far too much of my college dining hall -- and my college was ranked by the Princeton Review as having the worst food in the country.
