My first tarot deck (not counting normal-horoscopes.tumblr.com's "Normal Tarot," which is quite different)!
I'm not spiritual enough to believe in divination, but I've always loved the aesthetic of tarot's IDEA. It academically seduced me within minutes of our first meeting. So I've long wanted to have some cards to use for divining for fun, and to use to learn the meanings of each card reading, and the Rider-Waite Tarot is the most recognizably "classic" deck, imo.
This deck delights me in its tinyness. It's portable enough for my pocket, which means I can whip it out during DnD and before MtG games to divine my odd of winning. Tarot spreads being what they are, my readings are amusingly difficult to interpret through such a "success vs failure" lens, so that's been a lot of fun.
Also, my ADHD demands I carry no less than 3 separate fidget toys on my person at any given time. A tiny deck to shuffle fulfils that purpose nicely.
I think I might have to stop trying to stack the deck to spring Guerilla Tower Reading Attack!s on my friends, tho. I lost literally every game in my MtG draft tournament, the day I tried that on my friends to fortell them losing our match. The tarot spirits I don't believe in don't seem to like that much.