There was a thread on this topic recently. In a nutshell there is nothing that isn't skeevy. A good workaround is finding a college kid and signing up for SundayTicket-U for $125. To qualify you have to enter a current college student, their school and their birthday. If it checks out you can use your own credit card.
If you have no option but the skeevy sites, find an old laptop that is wiped clean of any personal data, go find a public Wi-Fi and watch. That way if you get infected with malware, there's little chance of harm. That's about it.