I watch too many anime series to remember their ridiculous names. And its hard to have a favorite because you realize that a lot of anime follow the same script.
"Boy has secret ability he is trying to control"
"Boy is surrounded by sexy girls but never makes a move"
"Guy has magical abilities and fights a sequence of increasingly strong opponents." And to spice up these things, you throw robots, monsters, apathetic characters, weird timelines, or randomness in it.
I don't mean to sound like a geek *adjusts glasses* but I've seen 100's of anime.
The only ones that I ever really gotten into emotionally was Elfen Lied and Chobits. No doubt they're popular aswell as they should be.
Funniest ones I've seen was Detroit Metal City and Seto no Hanayome.
Most suspenseful was The Great Teacher Onizuka.
The only manga I've somewhat enjoyed reading was Claymore, but usually I just watch the anime.
Oh, an interesting 2 episode anime I just saw is called Kiss X Sis. A friend of mine showed it to me. After watching it, I called him incestuous, a pervert, and a pedophile. I also thanked him on a nice find. 
Its ecchi btw, nothing too bad.
