There are many options available to you and it really depends on your specific needs and budget. Basic accounting software such as Quickbooks, Peachtree and Microsoft accounting have basic sales and/or forecasting tools.
Of course Salesforce.com and Saleslogix - two well known sales tools - are built and made in particular for sales.
All of these tools will only work as well as the data input into them so keep this in mind as well.
ACT! and Goldmine Software are contact management software leaders with sales components.
