Prodiamine 65 WDG is my favorite pre-emergent. It is a water soluble dispersion which is mixed with water and sprayed at 1.5 teaspoons for 1000 sq ft. There are a lot of threads in this forum on use of this product. It is very cost effective and works very well in my opinion. Much better than any Scott's combination weed & feed product.

Depending on where you're at in the country you might have missed your window for pre emergent application.

I'm using Bayer advanced for southern Lawns I think it works pretty good.

Another vote for Prodiamine. It will seem expensive at first but then you realize how little you have to use. The amount you pay for Big Box store product will likely exceed what you pay for Prodiamine in the long run.

In the past I used Halts with some effectiveness. However it seems with crabgrass, at least in my area, Prodiamine is more effective.

It will also provide some broadleaf weed control as well.