Primer, people, PRIMER!
I have combination (oily/dry, but mostly oily) and acne-prone skin. I have enlarged pores on my cheeks which I would LOVE to have reduced with the perfect primer. Also, since my skin is oily/acne prone, it can't clog my pores and make my acne worse. So I need something that will help tone down the oiliness on my face and keep my makeup on all day long
Rather than using a primer, try changing up your cleansing routine instead.
I had incredibly oily skin and flat acne. I started using Murad's Clarifying Cleanser (Item # 654228) with my Clarisonic Mia (Item # 1201904). The Clarisonic helps properly exfoliate my skin and the cleanser helps control oil and acne. Once I got my oil production and acne under control I found no need for primer or even foundation. I also use the Murad Anti-Aging Moisturizer SPF 20 (Item # 1224740). There are other great light moisturizers by Murad that are perfect for oily prone skin.
The Clarisonic is worth investing in. My skin has never looked better! The Murad products are worth investing in too. They last me a long time, a little goes a long way (especially with the cleanser).
A bunch of the women at Sephora continued recommending products and giving me samples until I found what worked well for me. So, just keep searching until you find what you like. Sephora's return policy can come in handy sometimes!