Any device supporting standard IPsec can be connected with pfSense. This page lists some that are known to be in active use, though it shouldn't be considered complete. While IPsec is a standard and pfSense utilizes a standards-compliant implementation, not all IPsec devices will interoperate.
... and we know there are many more. If you know of any specifically, please email coreteam@pfsense.org with info and a URL to this page. Thanks!