Moneyworks is the greatest Off-The-Shelf package accounting solution. Scalable, with flexibility to do own scripting, and simple enough for non-accounting or technie person to manage accounting and inventory management.
FreshBooks - The ideal accounting software for small business owners.
AccountEdge - AccountEdge is small business accounting software for Mac, Windows, and Mobile.
QuickBooks - Business runs better with QuickBooks, the #1 accounting solution for small business.
Akaunting - Free, open source and online accounting software for small businesses and freelancers
Xero - Xero is online accounting for your small business.
QuickBooks Online - QuickBooks Online is a Cloud Accounting for small business that can be used on iPad, mobile phone or computer to do invoicing, billing, run reports, or even pay employees online.