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.
Express Accounts - Express Accounts is a very simple to use and easy bookkeeping & Accounting software.
AccountEdge - AccountEdge is small business accounting software for Mac, Windows, and Mobile.
CashManager - Online & desktop accounting software
QuickBooks - Business runs better with QuickBooks, the #1 accounting solution for small business.
Xero - Xero is online accounting for your small business.
InvoiceTrackr - Business & Commerce and Office & Productivity