The reason there is no good alternative to PayPal, and especially an alternative that works internationally, is the regulatory environment around money transmission in the United States. If startups expect to solve this problem, there needs to be a coordinated effort to change that environment just as there was a coordinated effort to combat SOPA.
Exhibit A - http://www.thinkcomputer.com/corporate/whitepapers/heldhosta...
Exhibit B - http://www.plainsite.org/flashlight/case.html?id=716056
Exhibit C - http://www.plainsite.org/issues/index.html?id=1
Exhibit D - http://www.leginfo.ca.gov/cgi-bin/displaycode?section=fin...
To head off the most common objections: PayPal is grandfathered in at this point. You can only get away with breaking the law and hoping no one will notice for so long. The penalties for violation are criminal (federal felony), not civil. And yes, I'm biased as the head of a payments company affected by the law, but I'm not the only one, and I'm not wrong.
Also check out Dwolla - http://dwolla.com
Full service launch due in early 2012.
I can't say if they support international payments though (but they're a good "for US customers" option!)
We're going with Beanstream + Chargify. You might want to take a look at this: http://expletiveinserted.com/2011/10/02/stripes-new-online-p...
Unfortunately, Stripe is for USA-only.
An alternative is, as some people already mentioned, http://saasy.com/, which is a FastSpring service.
One of my businesses is an online retailer. We use PayPal Standard (but don't require a PP account) simply because the UI for generating postage and tracking shipments is very easy. USPS has an open API, but I've yet to find a payment processor that integrates shipping.
check it out