DVD: I received a copy of Tony Hassini's "Magical Illusions" on VHS as a gift some fifteen years ago - it's volume 10 of his "Easy to Learn Magic" series - and it's the only magic video I've ever owned. At the time, I was focused on my career in the defense industry, and really not interested in magic... especially not the magic he was teaching on this video, which appears to be targeted at the under-twelve set. But it did make me rather a fan of Tony Hassini, who's genuinely charming and enthusiastic about magic.
Book: Royal Road to Card Magic. It's only recently dethroned Scarne on Cards.
Trick: I don't buy tricks.