It really depends on what your company needs, but here's a list of free CRM solutions since you can't beat free.
At $12/user/month Zoho is a solid SaaS CRM worth checking out.
I would go with a scalable solution like SugarCRM. You can check out their pricing here: http://www.sugarcrm.com/page/editions-pricing/en
Many CRMs offer free or community editions, but important to note that many of these might have limited functionality or be missing important tools that you will need.