I used to own about 15 decks. Here are some I can recall that I disliked and got rid of over time:
Rider-Waite - What?! Yes, like many RW was my first deck and I did dislike it, but only on account of the flat, lifeless colours and the unimaginative "tarotee" crosshatched backs. They look like faded illustrations out of flight pamphlets with the attendants wearing medieval clothes! When I discovered other decks like Universal and Radiant with softer, more vibrant colours and the gorgeous starry night sky backs, I was hooked.
Cosmic Tribe - At the time I was incredibly overjoyed reading about a deck that wasn't heteronormative, that offered three choices of Lovers cards. But when I bought and used the deck, I had trouble with the psychadelic CGI hyper-New Age artwork. It also felt like I was an outsider looking in on a deck designed for rave culture or bohemians. I love that women and men of different body types are represented, but overall the deck just didn't resonate with me as much as I would have liked. I found the accompanying book with its talk of UFOs coming to hover over gatherings of druids and shamans confusing.
Robin Wood - At the time I wanted a deck devoid of Judeo-Christian imagery, and the Robin Wood was a nice deck. However I grew to dislike the artwork, with the hyperideal bodies and that Wheel of Fortune which to this day reminds me of old ads for feminine hygiene products.
Cat People - I'm going to be a crazy cat lady when I'm old. I adore the fluffies big and small, but this deck took too much work to adjust to. It felt like I was reading a deck taking place in a fictional universe out of fantasy books that required a ton of study and immersion to understand the dynamics of the culture the author was depicting. Eventually everything felt so alien that I gave up. To this day I've wanted to own the Tarot du Chat instead.
Mythic - I ultimately preferred the Olympus Tarot in the search for a Greek myth themed deck. The artwork on the Mythic is quite strange to me, with almost all the characters being spindly, pasty creatures. It was certainly a great idea to base each suit the story of one myth, but the artistic delivery really hampered it for me.