Technically it was Pokemon, but when I first started anime in general it was Naruto. Even though now I think Naruto is too much filler and a continuously milked cash cow, I am thankful for the series for getting me into anime in general. I've watched a variety of anime since then and found lots I love.
pokemon or yugioh, but the first time watching something i knew was anime was when i was 9 and watched naruto. i was already reading dragon ball and other various manga and my mother knew what japanese animation was so she kinda introduced me lol