Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Attendize Event Ticketing - Attendize is a free & open-source ticket selling and event management platform
Invitime - Meet new friends and challenge them to invite you
Ticket Tribe - Sell tickets online with no fees per ticket
RSVP Keeper - Online RSVP's made easy
pretix - pretix helps you to sell tickets for your event in an easy way. It supports multi-lingual events and provides a wide range of features