Normally paypal is very safe and I have done almost 50 transactions last year and never got cheated so far, hope it will never happen too...still there are some alternatives of paypal depending on country and company you are dealing with... alertpay e-gold moneybooker ecumoney
2checkout is good for merchant account, really had no bad experiences with them soo. Same applies to MoneyBookers. I'm feeling safe to send and receive money with those 2, not with PayPal.