I'm supporting the underdogs! I like Foodies, Fairy Tales, Street Art and Fads. These are the ones I feel can appeal to the masses (which means I can send to grandma, grandpa, uncle, aunty, father, mother, friends who live under a rock, friends who are Chinese-educated (I'm Chinese-educated, but I see Chinese-educated and English/Malay-educated people seem to come from different worlds. We have different taste in humor, fashion, etc... I don't understand half the pop culture references... here...

), etc.)
Other ideas are good, too. I just think that it's harder for the designers to come up with good cards from them. Unless if the person who proposed the idea works with the card designers?