The following are the most heavily sprayed crops according to the Environmental Working Group (as published in Alive Magazine May 2012):
apples celery strawberries peaches spinach nectarines grapes sweet bell peppers potatoes blueberries lettuce kale and collard greens
also, these are the top ten genetically modified foods:
corn soy cottonseed canola papaya sugar beets alfalfa golden rice salmon (farmed) pork