My favorite apps is importing different types of transaction to QBs from MS Excel. It would be convenience, save time and prevent mistakes.
Currently, I am using PRO IMPORTER.
Well I may be a little biased, but since you asked, I would have to say that right now Vendorsync has become the go to application for our company. Just the other day, my business partner was able to process 750 transactions in about 35 minutes with QuickBooks Desktop. To see him excited about the project I have been working on for a couple years, made it all worth it!