I doubt anyone is going to give you their account, and if they did, it would most likely be against that site's terms of agreement.
Also, the fact is, there are so many great free porn sites around that there's very little reason to ever pay, unless you're after that specific content - in which case, you already know where to go.
Most porn sites also have 3 day trials for cheap. If you want to know so badly, try them out.
On a personal note if I was going to pay for porn I'd probably go to one of the Kink sites (or do you get them all included? I doubt it, but haven't really looked into it because, as I said, you don't need to pay for porn
)