Credit Card Gateway Recommendations?

Ok, I know most of you integrate your code into some for of e-commerce to accept credit cards. I want to know what your favorite credit card gateway (authorization) provider is. Preferably, I am looking for a gateway that allows you to connect to their server directly through the code, via sockets, as opposed to posting data a URL and receiving the response on another script. However, if there is a solution to those types of gateways (that do redirect back to a script after authorization) to get around that and communicate directly with the gateways code from the SSL URL without having to do that redirect BS, that would be great too. I am thinking this could possibly be obtained using CURL from inside the code? Basically, let me know what your favorite company is to accept credit cards, as seemless as possible with your PHP code. And, hopefully it isn't any that require the actual browser to send data anywhere else outside my site (i want my code to handle it all behind the scenes). Thanks!!!