Being a freckly readhead, I'm a super advocate for wearing sunscreen on my face year round, especially during the sunny months. I've tried loads of sunscreen formulas including popular and never-heard-of brands which boast anti-pimples and sweat-proof everything, except that I'm already sweating through my first application before I've even stepped outside. So after many years of complaining, I've finally found one that I love and works for me: Neutrogena's Ultra Sheer Dry-Touch Sunblock with SPF of your choice (although higher is always better!). It dries almost instantly after you apply it so you're not left with a greasy face, and it's 100% hypoallergenic so no breakouts. Throw in a lovely scent, and voila! you have a perfect sunscreen. No excuses now!
Available at most local drugstores.