Well, if you are looking for merchant accounts then we would suggest you to go for Paypal or Google checkout. The reason for this is the fact that Paypal is the most widely used payment gateway in the world and you will receive payments instantly with Paypal :D When it comes to Google checkout, Google checkout takes some time for the payment clearance but the payment is well verified before you receive it so you are sure about the payments you receive
When you will use Merchant accounts from these payment gateways, you may be charged more but the benefits and features of these payment gateways are excellent and hence you can afford to spend some more to get merchant accounts from these payment gateways.