First and foremost, this is an evil question. @Devinrohers tagged me initially and I have been tagged in some subsequent challenges for it, so I will find the strength to do it, though honestly, this is always a hard decision to make, and my 'favorites' are constantly in flux. So don't take this list as my definitive favorites, but my favorites as of right now.
#5 - Tokyo Ghoul
This anime literally snagged me from the OP. Unravel is such an amazing song that I would've kept watching every episode just to hear it play again. But more than that, I love the struggle between good and evil within Kaneki, and the way he is ultimately not the goodest of good guys.
#4 - Digimon
Boom, my childhood in a nutshell. I loved Digimon ever since I first saw it as a kid, and I have never stopped dreaming of one day finding my digivice and finding out that I am a digidestined. The first Digimon movie is a work of art for me, and Omnimon is my forver favorite Digimon.
#3 - Hitman Reborn!
I've written about loving Hitman Reborn before. I even did it today! There really aren't enough words for me to describe how much I love this anime/manga. It was a major anime for me in high school and it continues forever in my memory as one of the greatest ever.
#2 - Nichijou
It's cute, it's funny, it's Japan as hell. I love every episode of Nichijou.
#1 - Naruto
Maybe I'm just basic as hell. My favorite anime/manga has to be Naruto, because of how much time I spent reading it/watching it. I even have a Naruto tattoo. Naruto has been a staple of my anime and manga career for as long as I've had one.