Market Place, near the corner of 6th Ave and Pearl, has a very large selection of fresh foods and ethnic delicacies, all at very reasonable prices. I've seen things here that I've found nowhere else, and a good mix of more common items such as yogurt, at excellent prices. They even have a 'wall of bargains' where you can get deep discounts (hint: it's towards the back, where the restrooms are).
I'd say that, outside of Grocery Outlet, MarketPlace has to be one of my top favorite grocery stores.
There is bus service - in fact, the #16 stops right alongside the side of the store - as well as a large parking lot.