Guidos is expensive and has the best produce hands down. It is sort like Zabars in terms of variety - cheese, organic and natural foods. It caters to a NYC crowd. Big Y has good produce, especially in summer and many local (Massachusetts and Connecticut produced) products. Aldis has lowest prices, good produce, but limited variety and a lot of their own brands rather than national brands. Price Chopper has OK produce, and tend to be cheapest for national brands. Target is good for pantry staples. Stop and Shop has so-so produce, but probably the most variety in general items.

Edit: keep forgetting Price Chopper is now Market 32 (same company) in this area.

The farm store on Fort Hill is good in summer. Also Jaeschke's on Crane Ave has a good garden center for veggie, herb, and flower plants and a pretty diverse farm stand in the summer. The owner can be a bit cranky if she is the one waiting on you. Whitneys on Rte 8 also has a great garden center/farm stand with bakery and sandwiches (a bit more expensive than Jaeschke's) and a pain to get out of if you are heading south back into Pittsfield.