Best Payment Gateway? UK / USA etc

i would like to know the best and easiest payment gateway.

I receive payments from UK and USA and rest of the world.

I have checked out the fees for some of them like worldpay / sagepay / paypal merchant / eway

worldpay and sagepay are both about 20pounds a month paypal is also 20pounds but charge more per transaction. eway is cheaper

which is the best though and easiest to setup and add.

sagepay and worldpay are the same cost pretty much so which is better?

i want the customer to be buying stuff easily aswell with their visa card (dont want them to be put off with clicking too much, or being confused etc)

cheers guys