Technically, Dragon Ball Z, when I was a kid and everyone was crazy about it. Or Digimon Adventure, I'm not entirely sure, but I was a huge fan of both. I'll be a little too honest and say I still am.
Though my first anime after I became an adult and came to realize those two are Japanese animations called anime, was... I'm not even sure about the name anymore. It was some random anime about a magic high school with some dude who sucked at magic but was still good in some other way. Just about the only thing I can remember about it was that the heroine had black hair and it had a good opening.