I guess I'm a bit late on this topic, but I still thought it'd be fun to put in my two cents.
I imagine vampires, appearance-wise, to
generally be relatively pale and sallow looking. As vampirism is a disease, I usually assume that if it
does alter your appearance, it makes you look just a touch underfed, possibly even borderline malnourished. It varies between person, obviously, but that's, often, the imagery I get when thinking about them.
As for personalities... well, each character has his own personality (Duh), but some very valid points were brought up, and I do agree whole-heartedly that at the end of the day, any character that remains a vampire is, simply put, a blood sucking parasite. There is a degree of evil in that. However, considering they're, once again, diseased, I assume the disease tends to alter the mind a little. Every organism has some kind of instinct to stay alive and maintain their population. A disease, I imagine, is no different. But how can a disease which
clearly makes someone evil sustain itself? Obviously, it makes even the kindest of people fall victim to the idea that they are, in fact, not evil. Their heightened senses are a
gift, not a curse. The need to leech off other peoples' life blood is simply a minor detail in it all. They were born to become a vampire, and if they cure themselves, they'll lose part of who they were. It's everyone else that are evil, for they don't understand how profoundly amazing it is to give yourself over to the Sanguine Gift.
I figure even the sweetest and most pure hearted vampires will eventually fall victim to pure evil, little by little. That, or they'll break free and cure themselves.
By the way, if it's not already
completely and utterly obvious, I really like vampires.