What's the best online payment processing solution?

I'm looking for an online credit card payment processing solution that can handle recurring monthly payments. I'm open to linking off of my site to a hosted provider, so long as I can sufficiently customize the look-and-feel. I'm also open to a lower-level code-it-yourself type of solution. Of course I don't want to spend too much time on this, and I want it to be cheap. :) Thanks in advance for sharing your experiences.