I wouldn't have closed the question because it was about Organic foods, but because it was too broad and didn't have "one" answer.
As a question it will prompt discussion and debate, which isn't what CookingSE is for. Stack Exchanges work best when questions are specific, and can be answered directly.
Hope you're not disheartened and will continue to participate :)
You could split your original question and ask two seperate questions from your original question.
Which foods are most affected by
pesticides? And which "organic" foods
are not noticeably better than
conventional non-organic versions?
Is actually two questions, I'd suggest the first could be region specific, e.g. the answer could be wildly different depending on federal regulations in USA, Canada, Mexico, European Union . . .
Also, what is "better" is often subjective, better from a health perspective, environmental perspective, cost, eithical to farmers . . .
I had several Stack Overflow questions closed until I got my questions detailed and specific enough.
Hope this helps.