Lots of reasons...
1. Organic food tastes so much better
2. It is good for our health not to eat pesticides and other chemicals in our daily diet
3. The local environment thrives on organically managed farms
4. You are contributing to a more sustainable economy
5. There is less waste and packaging used in many organic products
For a bit more detail read on!
Recent European research has highlighted the previously under estimated risks of eating a diet high in pesticides and antibiotics. The impact has significant results on human health and functioning. One of the best ways to protect your health is to eat a higher quantity of organic foods in your diet. Organic food is more expensive than the non organic variety and not all fruit and vegetables are equal. In the UK we have the 'Clean 18" and the 'Mean 18' list compiled by PAN. (Pesticide Action Network)
There are many reasons to buy from local producers; supporting your local economy and producers; eating according to seasonal supplies; reducing air miles; cut down on packaging;
this article from the Campaign to Protect Rural England goes into more detail
But most importantly it just tastes so much better.