Appearance

All of the Cullen family in ‘Twilight’ are described as breathtakingly beautiful; in fact, this and their aloofness in the cafeteria of the school is the first thing that draws Bella’s attention towards them.

"Their faces, so different, so similar, were all devastatingly, inhumanly beautiful." (TW1)
Although Bella is immediately drawn to Edward, we have frequent repetition of just how attractive all of the vampires are. Carlisle is described as looking "more like a model than a doctor" (TW24), Rosalie is so gorgeous that "the perfect blonde girl" (TW1) is "beyond belief", Emmett and Jasper are "intimidating and flawless", Alice is "striking" (TW Epilogue), and Edward is described as "dazzling" (TW2) and "too beautiful to be real" (TW13). Esme, whilst not as prominent in the novel as the others, still "had the same pale, beautiful features as the rest of them" (TW 13).
We discover that their perfect "marble" (TW13) features are merely part of their arsenal of weapons to make them enticing to their prey.

Ironically, many of the words Bella chooses to describe the vampires are an inversion of the stereotypical beliefs about the creatures. Edward is frequently described as an "angel" (TW23) or mention is made of "his angel’s face" (TW13). His eyes are "golden" at times (TW13) and the constant reinforcement of the positive imagery and implications supports the fact that the Cullens are, indeed, an altogether different version of vampire to that covered by legend.

It is worth noting that in Meyer’s world the transformation from human to vampire intensifies everything, including looks.
"The change into a vampire makes an average person stunning and a beautiful person absolutely beyond breath-taking. The reason Rosalie is such a beautiful vampire is because she was the most beautiful girl in Rochester, New York when she was human." (PC4)
Therefore, as Meyer herself concludes, all of the Cullens were physically attractive to start with, and their transition to vampire state merely enhances what was already there in much the same way that Carlisle believed that a person’s greatest gift was taken with them (such as Esme’s capacity for love) and made stronger.

Their movements are described as fluent and fluid, very graceful. Alice’s movements in particular are equated with being like "dancing’, and are set in stark contrast to Bella’s own clumsiness.

The uncivilised vampires are described somewhat differently, their walk being "catlike" and "on the edge of shifting into a crouch" (TW18). The woman is described as having a posture that is "distinctly feline" (TW18) From their description alone, they are seen as far more animalistic, wild and uncontrolled than the "urbane" (TW18) Cullens, although they are capable of cursory civility.

James is the only vampire in the book who isn’t described as attractive; in fact he is "nondescript" (TW18). Meyer explains this as James:
"was quite unattractive as a human. This is rare, because even vampires are drawn by beauty. They tend to, when looking for companionship, choose exceptional humans." (PC4)