As far as the "best wax", thats extremely debatable so I wont even get into it. Most guys will tell you that you need to order wax from some internet boutique to get the best, but I dont believe that is necessarily true. I have bought a few of these high end waxes, including Souveran for $100 a can, and honestly dont notice that much difference. You may notice a slight difference, but not one work $100.
Now, I believe that the key to making a car look good is not the wax itself, but the prep you do to the paint before you put the wax on. Make sure you clay the car to get any contaminants out of the paint. This is a must for a good looking car. Paint will feel as smooth as glass when your done as well. Depending on the condition of your car you may need to polish the paint before wax, or even compound then polish. For the sake of argument Im going to assume that your paint is in good shape and will be ready for wax right after a wash and a clay. In that case, just pick up some Meguiars NXT Paste Wax 2.0. It is probably the best OTC synthetic wax and it will last quite a while. It also shines great. I prefer the paste to the luquid but you can get either, doesnt really matter.
Sorry for the long post, hopefully this helps.