Mothers, Meguiers, and Turtlewax are probably the 3 most popular. And of course the best in quality. I like Meguiers clay bars best myself, and they definitely work. As OC said, get a paste wax. It takes longer to apply, but lasts longer. If your car is black, I find Turtlewax black to be amazing for that mirror shine finish we all love and want. For engine bay cleaning just get some simple green and a bottle of F21. The simple green worked wonders for cleaning away the grime and old grease stains out. F21 will make the plastics shine. And for the tire shine get that new turtlewax stuff. It seems to last several weeks versus a day or 2 like most of the others.