Erm, not in order...
1. Dragon Ball/Z/GT. A fan for nearly a decade, I just love it because it's just so awesome. Can be REALLY funny or REALLY serious to the point where it can make you cry (not just weak-hearted people, ).
2. Gundam SEED/SEED Destiny. Also have been a fan for nearly a decade. There's lots of drama, and I love all the gundams. Great characters with unique personalities along with a great plot.
3. Nurarihyon no Mago. Funny sometimes, interesting plot, etc. etc.
4. Initial D. Illegal street car racing. Who doesn't like that kind of stuff? XD
5. Detective Conan. I have no idea why I like it, I just do.
Honorable mentions: Pokemon, Vampire Knight/Guilty, Death Note, Dr. Slump, Prince of Tennis, Saint Seiya, Cardcaptor Sakura, Yu Gi Oh! (the original)