I'm terrible - I use neither. Insects don't bother me and if they do, I'm able to remove myself from the area.
Strega Mama
eating lots of garlic can also help with natural bug repelling
This is probably why they leave me alone. I eat a lot of garlic.
Why I don't bother with sunscreen is because I don't like the summer time hype. I wear transition eye glasses (so they go dark in UV light) and my glasses get darker in the winter than the summer - suggesting winter sun is more harmful than summer.
Not getting any sun is quite harmful - I read somewhere that there are more cancers caused by vitamin D deficiency than there is skin cancer. I think I only wore minimal sunscreen when I was in the Dominican. (Usually just put it on my nose and rub it off into my cheeks.)
If you're outside all day, they yea, it might be good to wear some. If you're indoors and only see minimal sun, I'd opt out.
If you're looking for top picks, No More Dirty Looks just started their Top 5 list:
http://nomoredirtylooks.com/tag/sunscreen/