Adapt is a B2B contact and company database provider across multiple industries. Adapt has 100 million business contacts, including industry-specific company database and contact information such as job title, direct dial, and email addresses.
It's affordable and they seem to be able to find a wide range of contact details. They have a nice Chrome extension which works well.
ZoomInfo is a growth acceleration platform delivering accurate and actionable contact and business information to empower your sales, marketing, and recruiting teams.
This one's for the big boys. It's not cheap, but Zoominfo is one of the market leaders when it comes to enterprise data needs.