To Go Organic or Not

Depending on what source of news you choose to follow, certain headlines claim organic is no healthier than conventionally grown foods while other headlines report the exact opposite. In fact, the results of two large meta-analysis (a summary of individual research studies) find both. So, what headlines do you believe? More importantly, is buying organic worth the extra cost?
Digging past the headlines, the studies examined in the above mentioned meta-analysis show that organic foods are significantly higher in certain antioxidants and lower in pesticide residue. In a nutshell, organic is healthier overall.
What foods to buy organic
The most important foods to buy organic start at the top of the food chain: meat and poultry, milk/dairy, and eggs. Next, foods you eat the most frequently and fruits and veggies with peels you eat or nooks and crannies that are hard to remove residue from such as potatoes, apples, pears, berries, lettuce, and spinach. The "The Dirty Dozen and Clean 15 of Produce" is a list of fruits and vegetables highest in pesticide residue and a list of non-organic foods that you can safely eat.
Don't worry about buying organic processed foods, like organic cereals and snack foods, if it's not in your budget. Just because a cookie is made with organic sugar and flour doesn't make it any healthier than a regular cookie!
How to keep it in your budget
Research local CSAs, or Community Supported Agriculture, that you can buy direct from the farmer rather than trying to buy organic at a grocery store. Other options are shopping at local farmers markets, Bountiful Baskets, or food co-ops. Buying locally, even if it's not certified organic, is just as good as buying organically grown food from the grocery store. It's difficult and expensive to become a certified organic farmer so many smaller producers opt not to become certified.
If you can't afford to buy organic, don't avoid foods just because they're not organically grown. As an alternative, always wash your produce well or use a pre-made produce wash to clean them off. You're still much better off eating fruits and vegetables than cutting them out in an attempt to avoid pesticides!
Resources
BaraĆski M, Srednicka-Tober D, Volakakis N, et al. Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses. Br J Nutr. 2014;112(5):794-811.
Smith-Spangler C, Brandeau ML, Hunter G, et al. Are organic foods safer or healthier than conventional alternatives?: a systematic review. Ann Intern Med. 2012;157(5):348-366.