Yeah, weed and feed does not work in my experience either.
What I have found works best is to spray in the fall. Sometime in late September or early October. Don't wait too long, or the weeds will be dormant, and your efforts wasted. You may have to spray both spring and fall to get ahead of it.
I use the generic pasture 2-4-D (I forget the name) from Fleet Farm. I also mix in some Ortho clover killer. I got about 2 acres, so I use a 20 gal pull-behind sprayer. Just don't get it on any young trees.
What 'Matthews' suggested above sounds interesting, but is not really practical on 2 acres.
It will take a year or two to get ahead of the problem. It's also an on-going battle since you generally can't control what your neighbors are doing (or not doing). Mine to the west has about a jillion of them on about 4 acres, so I never expect to be completely free of them, but I've improved to about 95% dandelion free over the past two years.