VitalSmarts has been on the Top 20 list since 2015.  Vitalsmarts has products and services based on more than 30 years of research and has helped more than 300 of the Fortune 500.  One of VitalSmarts best known courses is called Crucial Conversations.  Crucial Conversations is about resolving disagreements, building acceptance, speaking persuasively, and fostering teamwork and better decision making.  They hold seminars across the world and also do personalized consulting for large organizations.  Some of their other courses include Crucial Accountability, Influencer, and Change Anything.