I've been very happy with my Paypal personal account for a number of years, it's ease of use and reliability is unmatched. Integration with ebay has made it even more convenient to use. It wasn't until I started trying to start my own business that I realized how efficient it can be.
I upgraded my personal account to a business account and got started learning how to use the interface. It has some great accounting tools, including the ability to download your records in common accounting formats. You can tweak your profile so that the invoices, receipts and correspondence are complete and professional.
One of the best features of Paypal is their security, both buyers and sellers have a secure 'buffer' between them. Paypal now links to credit or debit cards as well as bank accounts.
Probably the most impressive feature for me is the Customer Service. I've had to ask a couple of questions and been amazed by the friendly, helpful service I've received. The representatives are highly trained and motivated and I'm quite pleased. Thanks, Gary!
Did I mention the cost? The services in the basic Business account are free, and the seller pays competitive fees. So far as I can see, I shouldn't need more.