This thread describes the criteria a buyer should use when buying fruits and veggies. I'll start... Potatoes: waxy or starchy, there should be no green under the skin - none. Avocados: slightly squishy. The really bumpy rinds seem to give the best taste (just my observation). Carrots: very firm - bend them and they should feel stiff. Best without tops, which are pretty but provide an escape route for moisture. Cantaloupes: firm. Some places I read talk about color but I go by smell, I think it's a better predictor. Onions - should be firm, especially at the root end. I'm sure PFers can come up with lots of produce tips!