I think Naughty America does a great job of keeping things fun and entertaining. Problem some people have is that they expect porn sites to each have 10,000 different movies. well guess what. there aren't ten thousand different ways to have sex. Sure you can have different stars, but how much deviation can there be without redundancy over such a huge number?
My remedy would be not to watch so much porn. not to be a dick, but hey, hit the refresh button on your brain once in a while. Take a week off, look at a Maxim or something.
Everything is relative, if you're doing anything too often it gets redundant. and I'm not joking about the numbers either. We're talking tens of thousands of scenes here, I mean, what do you expect?