I have a number of Park tools but don't consider any of them must have's. Well, maybe my set of spoke wrenches but that's it. I like my VAR bike specialty tools as well as the few Hozan's I have also. Park is a good tool maker, don't get me wrong but I don't think they make the best tools in every category.
Of the few I respect highly are their spoke wrenches, the wheel truing stand and the Euro-style bike stand...maybe their crank pullers to.