I have this friend, annoying for a chowhounder, who insists on eating breakfast 24/7. Thus, we end up going to Shari's or Denny's a lot. We've also tried lots of neighborhood places, though many of those don't stay open past lunch. About a year ago, we tried Elmer's. What a breath of fresh air after Shari's and Denny's. Most aren't open 24 hours, but the food is much better than the other diner chains. The meats are real, sliced turkey is actual roast turkey not processed meats, gravies taste like meat, the bacon is usually cooked correctly and not the worst stuff, etc. They even give you free cheese topped biscuits with your meal that aren't bad. The fries are nicely seasoned and crisp. I really enjoy their salads. And they have a tendency to use local ingredients, like tillamook cheese or whatever. Essentially, they're like Burgerville for a diner chain.
Anyway, I'm always disheartened to see the Shari's across the street from my nearby Elmer's packed when Elmer's only has a couple people. Elmer's is much better quality and has prices that are as good or better.