Ditto the Wilton sculpting tools. I use the veining tool for almost everything, including positioning the centers of flowers.

Of course all of the above mentioned, most especially, the Viva and fondant smoother.
One thing I use almost every time I decorate: My food safe paint brushes.
They are great for brushing away cake crumbs from the cake board after torting and dirty icing. They are also great when you get a bright red fleck of buttercream on a nice white finish.
You just take a damp brush, and swipe the red fleck away.

*a set of decorating tips including open and closed star, leave, dot, and a 1 M tip
*decorating bags
*rolling pin
*a tall turntable
*a big offset spatula

I also use always a vinil mat when working with buttercream or fondant because its easier to clean after, plastic wrap and cornstarch