Usually my favourite cards are the Empress, the Queen of Pentacles and the Three of Cups. These tend to be my favourite cards in my decks, the ones I will judge the rest of the deck by.
But I don't think I've ever seen something that caught hold of me more than the Two of Pentacles from the Deviant Moon tarot. I mean, I don't even like that card usually, but it's been almost all I can think about when I picture finally getting that deck in my hands. I'm going straight for that card.
If anything could give it a run for its money, it would actually be another card I don't usually care about, but this time in the Blue Moon (and the Maat? I don't know if/how much it was changed...) deck, and that card would be the Magician. Just gorgeous ;o;
Being a Capricorn, I also appreciate a well done Devil, as well. I don't think anything will ever top the Housewives leggy chocolate cake though.