At our house we try to buy organic. I would say we buy about 50%, sometimes less. That's not a lot. The key word is try.
A lot of times organic is not available. Sometimes organic is just too expensive!
I know that some fruits & vegetables are more important to buy organic than others. My rule of thumb has always been if we eat the skin (strawberries, apples) than I try to buy it organic. If we don't (pineapples, bananas) then I don't worry about it as much.
Well, I just found a handy, dandy guide on Environmental Working Group's website. Go to there and sign up and you can get an iPhone App or a Download of the Guide of What to Buy Organic.
I just downloaded & printed it and I'm going to hang it on my fridge!