Isaac's is far and away my favorite place to eat when I'm in South Central Pennsylvania (there are 19 of them around the area). The first thing that recommends them is their fantastic menu of creative sandwiches, all of which are named after birds. My favorite sandwich is a vegetarian sandwich called the Bird of Paradise: Swiss, Muenster, sprouts, mushrooms, olives, and tomatoes (no mayo for me) on rye. My favorite salad is the California Spinach Salad with spinach, mandarin oranges, golden raisins, toasted slivered almonds, and grilled chicken breast with poppyseed dressing. They have an extensive list of sandwiches, many of which are served on a hot soft pretzel in lieu of a roll.
The second thing that recommends them is that they are a locally grown chain that is deeply involved in the community and it's nice to patronize a creative and socially responsible company.