Been waiting for this one! Vette is probably my favorite character in the game- I say probably because Blizz, Kira, Quinn and Scourge are close. So thank you for this Companion 101.
Favorite moment is tough because there are a lot, the romance missions being most of them since I'ma sucker for those, if I had to pick it would be between the first meeting and her mission on Tat. Pretty big moments for her character...
Edit: Plus she's a great counter to my Sith's Dark tendencies, though we both share a great laugh at the more serious Darth's and Jedi and Crime lords and well..pretty much everybody. And add HK-51 to the list up there, he's giving Vette a run for her money.