For nearly all entities (such as businesses, schools, churches, clubs, governments) where a geographical locus or focus is evident, then a listing in some Regional category is the best place.
Some entities with geographical locus (such as universities, churches, symphony orchestras, associations of clubs, labor unions, and uncommon businesses[*]) may also be of interest internationally: and for those entities, a listing in Reference/Business/Society may also be a best place.
Entities that meet both criteria may be listed twice, and if your company fits the criteria, and you haven't already suggested your site to both a regional and a topical category, then it would help the editors for you to suggest it twice.
And -- I mention this not because it matters to an editor, which it absolutely shouldn't, but because it may matter to you -- nobody knows which kind of category will be reviewed most quickly, but with two chances for review in a right category, a site may get a quicker listing that way.
[*]"Uncommon" businesses are, roughly speaking, those that aren't everywhere, that someone might actually cross state lines to patronize: i.e. definitely NOT including restaurants, florists, travel or real estate agents, hotels, plumbers, etc. If a user wants to find a real estate agent in Lower Sniveling, Berwickshire, they can go to the LS category and look for real estate. But it would be stupid to go to the master list of ten billion real estate agents and hunt for the three names associated with LS or its suburbs. And it would be a waste of editor's time to build that list.