I notice that Paymate.com isn't listed. This is an Australian company that has the best security and fastest payments I've experienced. They also fight chargebacks for you, which few payment processors will do. Their customer service is brilliant, and your funds can't be frozen like they can by PayPal. If you're a seller in Australia, New Zealand or North America, check it out. (It accepts payments from more than 150 countries, from memory.)
Paymate.com is eBay's official alternative payment processor, too. After Paymate almost single-handedly thwarted eBay's attempt to force sellers to use PayPal in Australia (as a test before hitting the rest of the world) a couple of years back, eBay finally got the message.
Paymate is older than PayPal, too. And it has a consistent 80%+ customer satisfaction rate. It's payment buttons are easier and more flexible than PayPal's and it has an API, shopping cart, etc that clients can use.
BIG plus... Paymate.com accepts payments from CHINA, which PayPal doesn't. It also has a coveted Australian Financial Services provider license, which PayPal doesn't. They're not easy to get.
Hope this helps.