I chose hissing right off the bat and wish I wouldn't it's kind of annoying. Other then that, I use thirsty drinker, because I feel like no vampire every fully quenches the thirst anyhow. I also use wither stomach since she has no use for human food anyhow. day phobia which makes her tense during the day but I like that her powers should be weak during the day, I try and have her hibernating during daylight. Last I chose eternally sad and I love that weakness, it just works great for my sim and story, she has the gloomy trait as well.
The best ones IMO are eternally sad and insatiable hunger depending on what type of vamp/story you're playing. Worst is the hissing it's just annoying.