When it comes to bug spray, one size certainly doesn't fit all. The repellent you choose should depend on the type of insect you're trying to ward off. The CDC suggests using repellents with picaridin, IR3535 or oil of lemon eucalyptus -- like Cutter Advanced, Repel, Off! and SkinSmart -- to prevent mosquito bites. But if you're out to fight both ticks and mosquitos, reach for a spray with 20 percent or more DEET -- think Off!, Cutter and Ultrathon.