So far, I've enjoyed "The Claiming of Sleeping Beauty," by Anne Rice. If you like it (open it up and read the first 2 or 3 pages...you'll know by then), it's a trilogy and is followed by "Beauty's Punishment" and "Beauty's Release." Those probably fall into the "One-Handed Reads" category.

Anne Rice also wrote "Exit to Eden," which had some good scenes in it, but the second half of the storyline was irritating (the characters too, now that I think about it).

"The Story of O," by Pauline Reage, came very highly recommended to me. I own it, but haven't read it yet.

Most of the Clan of the Cave Bear series kinda falls into this category after the middle of book 2, actually. It's a little annoying if you're reading it for the rest of the story ("oh, her nipples are erect again, flip forward 5 pages..."), but might be enjoyable on a first read.

I know it's kind of old but have you read Anais Nin? Her erotica wasn't really my cup of tea, but it is well written and sexy. Also, Henry Miller - Sexus, Under the Rooftops of Paris, and one of the Tropics books (sorry, it's been a long time since I read them) are basically porn masquerading as literature. Under the Rooftops, in particular, is spectacularly filthy and perverse.

VOX by Nicholson Baker
http://www.amazon.com/Vox-Nicholson-Baker/dp/0679742115/ref=ntt_at_ep_dpi_5

The Fermata by Nicholson Baker
http://www.amazon.com/Fermata-Nicholson-Baker/dp/0679759336/ref=ntt_at_ep_dpi_6

Both unique and enjoyable to read. Excellent writer.

The "people that might actually exist" might disqualify this one, but I'd recommend "Soulless" by Gail Carriger. The romantic/erotic tension is handled quite well, and the language in the book is delightful. The female protaganist approaches everything from a witty, scientific perspective that is quite refreshing. She's also dismissed by society as a plain spinster bluestocking, so no blonde bombshell ninjas here.

However, it's steampunk victoriana with werewolves and vampires, so...there's that. I liked it. It's hot.

The "Claudine" series by Sidonie-Gabrielle Colette are very well written and pretty steamy. I wouldn't exactly call them "dirty", but they are incredibly sexy.

Surprising, but I found some fun, well-written smut on Literotica recently. Not a hold-in-your-hand book, but great for engaging your mind AND other parts. The main characters are a very ordinary young man and a stunning succubus, but don't let that stop you.  As an added bonus, the story happens to be set in Seattle.

I can't get the link to post from my phone but the series is called Angels, Demons, and Alex.  

Kushiel's Dart has an interesting plot, likeable characters, and sex scenes. It may or may not be what you're looking for, but I really liked it! The author is Jacqueline Carey.

I remember enjoying the sex scenes in A Song of Ice and Fire by George R.R. Martin. But I read that when I was younger, so not sure how well it holds up now that I am a jaded adult. : )

The Marketplace series by Laura Antoniou. She's a great storyteller and I love how beautifully she creates and maintains the characters' different voices.

I love all the dirty girl books here, but someone's gotta speak up for the practical and basically-non-fiction (&fun) dirty books too..

namely,

The Sensuous Dirty Old Man by Dr. A aka Isaac Asimov

Yes, THAT Asimov.
Well written for sure (and not at all about ninja Phds with a mansion in the Hamptons). Also: funny as fawk.

I also like the onehanded collections, like 'Playing With Fire: taboo erotica', 'Afternoon Delight-erotica for couples' by Alison Tyler and 'Girls on Top - explicit erotica' by Violet Blue. Granted, many are ken and barbie-type paper dolls, but sometimes that's what's needed. ;)

Vox, by Nicholson Baker

Penultimate Hustle! It's not out yet, so read Radar Love, first, the first in the series. But PH has full on sex scenes that are inside of an amazingly well-written story. Thanks to ebooks, it can be released as is, fully x-rated, instead of being watered down for a print publisher. Message me on Facebook and I'll send you a review copy. Actually, Pageburner has some hot scenes in it, as well.

Pageburner

http://www.amazon.com/Pageburner-ebook/dp/B006IJUGVU

Radar Love

http://www.amazon.com/Radar-Love-Ultimate-Hustle-ebook/dp/B006LRKASI/ref=ntt_at_ep_dpi_5