I've been using Zoho's suite of products for over 15 years (before they were called Zoho). They offer a CRM which is very good, has many integrations similar to other CRMs, is very customizable, and has many functions which can be automated (lead generation, campaigns, etc.).

Zoho offers a package of over 40 apps for $360/year per user which includes Zoho CRM and many other useful apps (Mail, Books for accounting, online chat, etc.). Worth looking into, especially if you will use the other apps that Zoho offers.

Cheers!