Hmmm, that's tough..
All around, my favorite Tarot cards are
Ace of Chalices (I feel that's my personal card)
Strength
Two of Chalices
The Moon
And when I get a deck, I usually have to check out each Lover's card.
For the Universal Fantasy deck, there are 4 that I am fond of:
Magician, Lovers, Strength, and 2 of Chalices
I think 2 of Chalices is my favorite, though.
New Palladini
Toss up between Strength and The Moon
Manga Tarot
It's harder for me to decide here.
6 of Chalices, 10 of Chalices, 4 of Pents, Justice, Lovers, and 5 of Wands
This one's a toss up between Justice and Lovers