I believe that the best anime to capture someone into the Otaku life is Ouran high school host club!
There's drama, romance, laughs, pretty boys and all the stereotypical anime tropes that we all know and love that's perfect to get anyone hooked on anime!
Seriously though, I think that this is one of the best animes to start with because it's one of the classics that EVERY anime fan has seen. It was the first official anime that I watched back when I was getting into anime (not counting Pokemon or sailor moon).
I'm also kinda biased because this is probably my #1 favorite anime.
@InVinsybll