Arbor Farms is my favorite grocery store in Ann Arbor, and their hot-food counter is fantastic. I recently bought their weekly special, which was a vegetarian Reuben with marinated tempeh, sauerkraut, onions, and vegan dressing. It was excellent. If they don't have a similarly veggie-friendly special when you're there, buying one of their chickpea walnut burgers (vegan warning -- it has eggs) and crumbling it atop a side salad is always a good bet. The homemade balsamic dressing is awesome.

For out-of-towners, this is a good chance to sample some locally grown food. It's cheaper than Plum Market, and the hot-food options are MUCH more vegetarian friendly.

Arbor Farms has a great variety of most anything you'd want to find in a grocery store or a health-food store. They also stock a lot of local products (e.g. local tortillas, tofu, etc). Unfortunately, they rarely carry local produce. Most of their items are more expensive than at the People's Food Coop or Whole Foods. It's good to support this locally-owned store though!