Hi M.---First, go to www.ewg.org and look at their sunscreen database. You will find which ones are best for minimizing chemical exposure and toxicity. They will give you recommendations for good sunscreens to keep you protected as well as minimizing your risk of exposure to cancer causing chemicals. You'll then have to decide on what compromises you are willing to make for convenience.
Also, look for info on spf numbers. I've read, and it's been awhile, that you really don't get any more coverage for #'s over something like 30. So, you might be wasting $ if you pay much more for that.
Lastly, if you have acne problems, I'd like to ask you this ?. Do you consume a lot of dairy products? Dairy is a HUGE culprit when it comes to acne. I can send you documentation of that, if you'd like. You can also learn more about 'why not milk' at www.pcrm.org. Put diary in the search box. Oh, this is last...eat lots more red and orange foods. The nutrients in those actually act like sunscreen, if you eat enough of them. My family uses a whole food supplement that has lots of carotenoids, like lycopene and lutein and we can be out in the sun A LOT longer than ever before. So I know it works. If I can be of further help, please feel free to contact me. Good luck and have fun with your research. Be well, D.