I just realized that we didn't have a dedicated thread for HG primer recommendations. Voila!
My current love is the Hourglass Mineral primer. I have oily, acne-prone skin, and didn't like the feel of silicon primers. This one (which is different from the serum + primer, which I understand isn't great for oily skin) goes on very smooth, feels weightless once applied, and absolutely works without breaking me out. I give it two very enthusiastic thumbs up in spite of the $55/1 oz. price tag. You can get a 0.33 oz tube for $18 to test it out, though, if you're reluctant to plunk down that much cash on a new product.