Urban Decay has 20% off everything right now with code TAKEITOFF. Just today and tomorrow, but the code works on the sale section. Their primer potion is already 50% off, so with the code it's down to $8. That is a decent price for a good eyeshadow primer (reviewed here in Eden). There are also palettes and other things in the sale section. Shipping is free over $50; otherwise it's $8.
Zoya has $5 off plus free shipping on orders over $25 from now until Oct. 18. Zoya is my favorite nail polish brand, I think. So many interesting colors (some swatches in my Zoya tag).
Those are the best I've seen today. Anything good I missed?