The best scratch post I ever had, and which encouraged even my huge, bobcat-sized naughty boy to stop ripping up the furniture was one I made myself after commercial scratch posts failed.

I took a board about 2 1/2 feet long, wrapped it very tightly with sisal rope, and bolted it into a stud on my wall. I rubbed catnip on it and it didn't take long for my big boy and two other cats to use it exclusively after I gave them a little instruction/encouragement. It was very solid and they loved scratching the sisal. It lasted for many years.