I'm oily with acne prone skin and I can't use the silicone primers like smashbox or the monistat "dupe" that most people use. They do make my skin smoother, but do almost NOTHING as far as mattifying the skin or helping my makeup last longer. They almost seem to have the opposite effect and seemed to increase oil production.
I've found one GREAT oil control primer...in the drugstore and its about $5. Its by Black Radience and the reason why I love it is it contains Kanolin clay, which is an oil absorber. It keeps my makeup in place, keeps my skin matte but not too dry, and bonus is that it makes an EXCELLENT eyeshadow primer too! I also use a powder primer from Meow Cosmetics that has Kanolin Clay in it and I'd been wondering if I mixed a bit of the powder with my moisturizer if it would make a good liquid primer for liquid foundation...then I stumbled upon this in the store and I've been in love ever since. Black Radience products are in Walmart, CVS, Rite Aid, and Walgreens I belive.
The other primers that I swear by us the Sephora brand oil control primer, and Korres Mattifying Primer. The Sephora is about $17 and the Korres is a bit more expensive at $34. Love them both, though the Korres works better for me in the spring/fall. The Sephora works well year round but the black radience is my go to primer in the hot, sweaty, humid summer months. I've been using it in the 100+ degree heat we have been having and my makeup lasts a good 7-8 hours with only a few blots after about 5 hours...and I'm outside in the heat a few hours daily.