All alternatives are good but we prefer Pipedrive because of its great customization and most fit for company/business development.
Sleeknote - Set up lead capture forms on your website in minutes. No coding required. Sync your new email leads with your favorite email service provider. Try for free.
Zoho CRM - Omnichannel CRM for Businesses of all sizes
OptiMonk - OptiMonk is the most powerful Onsite Retargeting platform, that helps you increase the conversion rate of your site, and get more leads by recovering lost visitors.
Insightly - Insightly is the easy, powerful and affordable online Customer Relationship & Project Management Software used by over 400,000 small businesses world wide
Agile CRM - Agile CRM (Customer relationship management) features modern CRM with marketing automation, social suite & web analytics, allowing small businesses to sell and market like the Fortune 500.
Freshsales CRM - A full-fledged CRM for high-velocity sales teams.