The Curse of Strahd (5e) and Expedition to Castle Ravenloft (3.5) modules feature the use of fortune teller cards to determine certain aspects of the adventure. For Curse of Strahd, the deck of cards is called a Tarokka deck, and in Expedition to Castle Ravenloft you're told to use a Three Dragon Ante deck. In both cases, you also have the option to use standard playing cards instead.
I've been meaning to purchase a Tarokka deck because I do love cards and the art is, predictably, amazing. But in New Zealand, a store with the Tarokka deck in stock is suprisingly difficult to find, and a deck isn't exactly cheap. It's not very expensive, but when I'm standing in front of a bookshelf full of amazing D&D books with $100 NZD in your hands (yes, a $50 D&D books costs $100 NZD after importing and currency conversion), I find a deck of cards a hard sell.
Of course, you can also use a Tarot deck, which is the obvious inspiration for Tarokka. However, I also don't own a Tarot deck! I do intend to get a Tarot deck because they're great for game design, but so far I just print a black-and-white deck on card stock when I need raw materials for a game design. Until I find a Tarot deck I really like (and there are many brilliantly designed ones out there), I'll definitely make that purchase, but so far I haven't needed one enough to justify the hunt.
By chance (or was it...fate?), my co-worker Laurie got me a deck of cards asa Secret Santa gift a few years ago. It was a standard poker deck, designed by Gent, called the Fae Deck. The Fae Deck, as its name suggests, is built around the Seelie and Unseelie Courts of the Faeries. All of the cards are black as midnight, with light grays and white and sometimes even black (there's nothing more stylish than black on black) ink. The designs are vaguely celtic and all-round old-world.
The face cards, used as the "focus cards" for Madame Eva's reading, are beautifully illustrated etchings.
Because I didn't purchase these cards myself, I don't know how much they cost, but it was for an office Secret Santa celebration so I believe the deck was probably quite affordable.
At first, even with my fancy Fae Deck, I was a little nervous about using playing cards instead of a Tarokka or Tarot deck. I felt like my players would surely want an image to look at as their fate was being decided upon. I was incorrect, and I think I wasn't accounting for a few things.
For me, the fact that Madame Eva's "humble" deck of cards is actually a designer deck is what brings the cards into the D&D world. I do feel I'd be feel a little more awkward using a standard set of Bicycle poker cards for Madame Eva because those are so mundane in our world.
A nice designer deck takes the cards away from Poker, puts them into D&D, and Madame Eva does the rest.