There are few online hentai paysites that actually feature content legally, which is one of the reasons why I am able to recommend Total Hentai as a great site to view all your favorite hentai titles at and any that may tickle your fancy after reading a review here. It's explicitly promoted by Adult Source Media, one of the main hentai licensors in the US.
The other great thing about Total Hentai is that you not only get access to the one site, you get access to their entire network. And unlike all the other hentai sites out there, Total Hentai is actually run by a major porn company, which means you get access to a spectacular network of sites with some fantastic real life content. Of particular interest are Horiental and Fresh Outta High School but there are so many more in there that it's just crazy.
Right Stuf sells everything from anime videos to bishoujo games. They have a comprehensive selection of US anime releases, but they don't have much in terms of Japanese imports.
Looking through their catalog, you'd think they were just like any other online anime retailer. But what you should really be checking out is their Bargain Bin, which features original anime videos for as low as US$3 and there are hundreds of good titles to choose from.
Another section you should not miss: Weekly Specials! Want to get the whole Irresponsible Capt. Tylor or Boogiepop Phantom DVD sets for a mere US$50? The Blue Seed DVD collection for US$30+? This is the place. Right Stuf recycles these special bargains so if you miss one chance there's always another. The list changes every Thursday so don't forget to keep an eye out!
Yes, I have personally ordered from Right Stuf so I can vouch for their reliability. Probably the only negative thing about them is the rather slow processing to shipping stage. But if I you can get DVD sets for impossibly low prices then I'd say it's worth the wait.
You'd be surprised at the sheer number and variety of anime titles they have in stock. Amazon.com carries both tapes and DVDs. They don't have hentai titles though.
Amazon.com is the best source of English-translated manga since they have the widest selection. They are also cheaper than bookstores or comic shops, tax-free to boot!
Amazon.com's pre-order prices for anime DVDs are pretty good, especially for boxed sets. They also have a section called Today's Deals, where you can get anime DVDs for about US$10 and up.
Amazon.com's customer service is fast, friendly, and simply unbeatable. Once they shipped me the wrong item, I received a replacement in a couple of days! Get this -- I live in the Philippines! They told me to keep the wrong item since it'd be too expensive to ship from where I was. You can't go wrong with Amazon. They really take care of their customers. In fact most of my anime DVDs were ordered from them.
DLsite is the largest legal location to pick up all your hentai related needs. Bringing us the newest content straight from Japan, DLsite is filled with all manner of Bishoujo Games, Erotic Doujinshi, HCG, and even some of the latest hentai episodes in Japan come out on there. Given the content is almost entirely straight from Japan, most of it has not been translated. Some real gems that you cannot find anywhere else are located on DLsite, and I highly recommend you go check them out to see if you can't spot some of your favorite characters in compromising positions!
DLsite deal exclusively in downloadable content, so there's not waiting. As soon as you buy something you can downloaded it immediately and as many times as you need.