Killer bug spray is an absolute essential item for camping. I don't care where you are, unless there is feet of snow on the ground, biting insects are around and you've gotta be prepared. With all the infectious 
diseases (yellow fever, west nile virus, rocky mountain spotted fever, lyme disease, etc) from mosquitoes and ticks, I can't stress enough the importance of having a physical and chemical barrier between you and potentially dangerous insects. This version of Repel is almost 100% DEET. It's technically 98.11% because it's hard to actually achieve 100%, but for marketing purposes it calls itself DEET 100.You want a high number because DEET is what does the dirty work and keeps insects away from you. It's mechanism for action is that it attacks the insect's olfactory receptors and makes you very unappetizing to a potential biting insect. DEET is safe and has been approved for use in the United States for over 50 years, it is Centers for Disease Control recommended as an insect repellent. In this day and age, many people (including me!) are looking for what is 'natural' or 'organic', but in the case of protecting yourself from insects and potential diseases...just go with what works. Kids need to avoid direct contact (clothing application OK) and I wouldn't spray this on my face. Make sure you get a thin film over your skin to get the best possible prevention and wash your hands after application.
Repel 94108 100 Insect Repellent Pump Spray, 98.11-Percent DEET
This product has been a mainstay in my hiking backpack and I keep another bottle in with my camping gear. It is an essential piece of equipment. I do most of my camping and hiking in the late spring, summer, and early fall when bugs are their peak. Using Repel DEET 100 is the difference between having legions of bites on my legs and arms, and just having a couple here and there. I'm not going to tell you that this product will with 100% certainty make sure you don't get bit, but it dramatically reduces how many bits you'll receive. Since it lasts 10 hours, that will give you a full day of being outside. I will typically take a dip in a lake or stream to get it off me and then reapply the next day.
Price: $12
Available from Amazon