I've tried tons of primers, and it really depends on your skin texture and specific needs, but I'm really loving the Tarte Clean Slate Primer. My skin is acne-prone but on the drier side, and this primer keeps my skin smooth and nourished, providing a great, even base for makeup that lasts ALL day. I also love that it has natural ingredients that are good for your skin. On days when my skin is red and blotchy though, I still like to use my Smashbox Color Adjust (Green) Primer, because it helps cancel out the redness and it still provides a smooth base for foundation. The original smashbox primer is pretty good to though. If you have SUPER dry skin, you might want to try the Korres primer, which moisturizes AMAZINGLY, but doesn't make your makeup last as long as other primers might.