Well I love Paypal and have had no problems they put a small charge on payments that you accept and that's in you can credit it to your bank card immediately.

I also had experience with Google checkout very nice application and really fitted into my site well without messing its look and feel out.

http://checkout.google.com/sell/

I can't say I've had any other hands on experience with any other company's maybe another delightful member of WebsiteBabble can awnser your question more efficiently.

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