I am a fan of the Rider Waite Tarot and I use them regularly; however, my first deck and the ones I use most often are my Marseilles tarot cards.
I can't really say for certain why they appeal to me over the others. I think it has to do with the artwork and imagery, and the history behind each deck. I find both visually enticing and I connect to their origins for different reasons. I chose the Marseilles Tarot because it was a French deck, and my direct maternal line is Acadian French (not the exact same, but it felt familiar enough). I like the simplicity, but also the hidden intricacy in them. I have also learned the multiple variations of names associated with each card in the Marseilles deck and how it could be applied to it (the French word and it's meaning). I liked having something like that, their history, and multiple names, to learn. It felt like peeling the layers of an onion or getting to know a beautiful and mysterious woman. She makes you cry and sweat and work for her secrets as you fall more and more in love with her.
With the Rider Waite, they are just beautiful. They appeal to the artist in me and they feel like a labor of love. I think that's what's truly great about having so many options is that we can find the ones that speak to us, and which ones may work for different situations or times in our lives. The decks can grow with their readers, and perhaps which ones we are drawn to reveal something about us.