Are you looking for a foundation, concealer, or both? And do you have breakouts all over, or a few spots you would like to cover?
If you have acne all over, you probably don't want to risk aggravating a breakout. I would try a foundation such as Clinique Acne Solutions, which is medicated and neutralizes redness, making your skin look more even: http://www.sephora.com/browse/product.jhtml?id=P25
If you need a good spot concealer, I like Make Up For Ever Full Cover, because it has a thick, dry consistency that makes it cover really well and stay put for hours. It's highly pigmented, so a little goes a very long way: http://www.sephora.com/browse/product.jhtml?id=P15
Well firstly, happy birthday ^_^
I have got to say, if you haven't tried MUFE (Make Up For Ever) than you absolutely must. Whether I'm breaking out or not, it just makes my skin look amazing. I suggest using a brush and never your fingers (one, to help prevent breakouts; two, for a better finish) I use MUFE's wet foundation brush; and the HD Finishing Powder is a must for me at least, it sets the foundation and keeps it lasting all throughout the night. I used to get the primer but after a few months never saw a difference in results nor durability if you will, so I don't think that's necessary.
I've always been complimented on my skin for looking perfect and not cakey. Some prefer a more opaque finish but I feel that a little translucency to one's face looks better - only using a little concealer for those problem spots.
Also, for eyes I say Too Faced's Shadow Insurance, and Too Faced's Naked Eye Palette. Remember to sweep one neutral skin-tone or "base" color from your eyelashes all the way up to your brow bone. It keeps your darker colors blending well and having that shading/smoking effect ^_^
Here's an unedited picture of my makeup using all I've suggested:
I agree with katie1724 that for all over coverage and a reduction in redness, Clinique's Acne Solutions Liquid Makeup would be best. It is medicated to help stop future breakouts, too. You can find it at: http://sephora.com/browse/product.jhtml?id=P259605
For spot coverage and spot treatment, I would recommend Clinique Acne Solutions Clearing Concealer, which you can find at: http://sephora.com/browse/product.jhtml?id=P244700
I hope this helps you.