The only fruit I really notice a difference in is tomato. I figured it was probably because not only are factory tomatoes sprayed, but they have been bred over the years to withstand long shipping distances, so they're not as juicy. Someone on this board also told me that they are force ripened. The organic are less uniform and a brighter color, and the taste is close to what I remember from when I was young.
Oh, and last year I got some organic strawberries that were so good I wanted to get on my knees to the strawberry goddess. Factory strawberries are another fruit that is forced ripened, which is why even if the outside appears a beautiful red, the inside might be pink or even close to white - not tasty.
Other than those two, I can't really taste the difference between organic and non-organic fruits and veggies.
ETA: Not sure if this is true, but I think children have more sensitive taste buds than adults, which is why we sometimes talk about 'developing a taste' for something.
"Right is right, even if no one is doing it; wrong is wrong, even if everyone is doing it." - St. Augustine