Eat 'n' Park is one of the great things about the Pittsburgh area. Never have I seen a chain diner where the food is so consistently good. Eat 'n' Park blows Denny's and King's out of the water in terms of quality.
Now, that doesn't mean that it's the best food ever! It's still diner food, and some of it is still going to feel cheapish. BUT their shredded pot roast is excellent, their steak and cheese isn't very Philly, but is very tasty, and I rarely have a bad server here.
If you want some eats and a bottomless cup of coffee, seek out an Eat 'n' Park!