uugggghhh these are my 2 least favorite ponies... but i only dislike Rarity because of bad writing, i think she has real potential. RD on the other hand... she is such a hollow character, the tomboy trying to rise to the top, who always bosses everyone around, and they do nothing about it, constantly begging for attention, and incredibly self centered and proud, she is not even that loyal. (But then again Rarity isn't all that generous, but at least Rarity has hope.)
Rarity it is then