The first site I joined was Sapphic Erotica as I had been a longtime fan of their low-res freebie sets and videos. As the price was pretty cheap, I joined up and remained a member for two months before buying the six-month deal. I was very happy with the site during my entire membership.
These days, I budget for $30/month membership to a porn site, and I bounce around from site to site just to see what's out there.
Look, it's pretty cheap to buy one month membership, and if you join a good site, the quality really speaks for itself. I can't imagine not having access to quality porn, it's kind of like going from cassette tapes to CD. Just do your homework, find some reviews (a la Rabbit's Reviews and Freeones Reviews), and make sure you're joining a site that promises quality content that interests you and plenty of content to choose from.
Hope this helps.