Ask HN: What's a good recurring payment system?

I'm running a mini web host where I host sites for some designers and developers that I know. I'd like to set up a subscription/recurring payment for these sites, as this is the way that these guys prefer to forward the payment from their clients. It should accept debit/credit cards, of course.

So, what do you use for this sort of thing? PayPal? Authorize.net? Something else? Thanks!