For accounting: QuickBooks or AccountEdge. These are about equal in functionality. I would rather use AccountEdge, but if you have to send your files to a CPA, he/she will likely steer you to QuickBooks.
For general office: Microsoft Office is the standard of the industry. Recently I saw another "Office" for Mac at CompUSA that is supposed to be totally compatible with the MS product, but I can't remember the name of it. Much lower in cost.
It's your call.
