title: Payment Gateways with the best API?
body: <p>Our company will soon need to integrate a payment gateway with our PHP web application for our users to be able to pay a "conference registration fee" using a credit card. Before defaulting to using Authorize.net, I want to find out from other developers which payment gateways you have used, and can recommend, that has an easy to use/integrate API.</p>
  
  <p>FYI: Our company is in the U.S.A.</p>