Sure, if by "watched" you mean really digging into an anime, and if by "anime" we're talking about stuff from Japan, then my first mind-blowing experience was with "Princess Mononoke". I saw it on TV and it was totally different, super deep, and nothing like the cartoons I was used to. As for a full series, that's gotta be Evangelion. I binge-watched the whole thing in just two days. I would still rank them as one of the top anime I ever wached.