Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.
EventsBase - Find the best professional events nearby or globally
Skittish - This is no webinar.
Rally by Eventbrite - Find the best local events and rally your friends to join
Komos - komos.io is a free tool, that helps you discover comedy events near you and get event tickets for your favourite comics.
Calendall - Follow the best events online, without leaving your couch.