Well that would be a tough billing for any actress to live up to. She's got her own look, which is unlike most of the other actresses on the show, which may substitute for being genuinely orders of magnitude hotter than anyone else.
On a more general Game of Thrones note, I'm still trying to figure the Tyrell's out. Are they really Lanisters in flowers, or do they have a deeper sense of morality and nobility that motivates them. It's hard to say since we haven't had any Tyrell POV characters, but Margery at least in the novels seems genuinely decent. Loras of course has issues vis-a-vis Renly, but beyond that it's hard to get a read. Then of course there's Mace and the Queen of Thorns!
This conversation may require spoiler space for those not up on the novels, but I am curious what others think.