Got crabgrass big time in Allen, Texas

I applied the pre emergent and I am told due to the cold weather in our area that it did not do its job so I look others have a yard full of crab grass. I have not been able to get any good input by googling on the web regarding which would be the best chemicals to use for this weed. It seems like the traditional Ortho and others are so watered down that repeat treatments are the order of the day. Does anybody have any success stories in this area. Thanks