I like the way that Template Monster works in which they give their clients the options of either using PayPal (recommended) and 2CheckOut (which basically accepts credit cards without the sign-up hassle).
Of course, there have been some disgruntled customers against 2CheckOut lately; but just like PayPal, you have to be careful and go with caution anyway.
i actually bought the domain webmasterads.com from a reseller and i paid through 2 checkout because he said that paypal doesnt give the seller that many rights i.e. the buyer can just withdraw the payment
The main problem I think was that the orders where taking a long time to be processed and email notifactions where not been sent out when orders where made ect. 2checkout also have forums and they say they are considering closing them, I think its beacuse it gives them such bad publicity.