Dinner in Hays, KS
These are the two best places I have found.
I prefer Gella's for ambiance and food.
Professor's did have a good green bean-dumpling
521 E 11th St
Hays, KS 67601
Phone: (785) 625-9930
Gella's Diner & Lb. Brewing Company
117 E 11th St, Hays, KS - (785) 62
I can't second Al's. I was disappointed with pretty poor chicken, and without that there's nothing much else to recommend. Now, although not tried, there are (as almost always in W Kansas) good looking Mexican places, some quite authentic, by their storefronts.
But Al's does have character, if that's more important in the decision. It's not a chain.