Paypal is the leader. You get what you pay and the fees are much less then other money houses. I've been with Paypal for six years and never had a problem with them. If you do, they have "live" support unlike others who use email for support
I agree, PayPal fees DO suck and add up to ALOT. But its pretty much hand in hand. Because they are the most accepted, even though I hate the fees, I think I'll still stick to PayPal, just because its easier for everyone.
I agree with eddy2099. It is nice to read a lot of suggestions here but the question is are you selling anything online? I have been selling digital products (see my signature) during the past two years and found that nothing beat PayPal.