I like Danny Phantom a whole lot -- the script is sarcastically hilarious, actually kind of mature in its humor, and the characters are well-drawn and rather likeable. :) I became hooked on the show when I was channel surfing one Saturday afternoon and chanced upon Nickelodeon, where the first episode "Mystery Meat" was being aired. I instantly latched on Danny, because he's so cute (tee-hee) -- I'm partial to geeky, unpopular teenage boys. The bit about him having a secret identity struggling to be half-boy, half-ghost, and being a full-time superhero was pretty cool. Plus, I liked the dynamic he, goth girl Sam, and techno-geek Tucker shared, as best friends.
About two or three weeks later, I caught the episode "Fanning the Flames" -- in the Asian region, I believe, the episodes weren't shown in order. The episode was very DannyxSam-centric -- they even kissed for the first time there (of course, it was the "fake-out make-out," since Danny wasn't exactly himself. More about the episode here). And being the hopeless romantic, OTP-hunting fangirl that I am, I was instantly a fan of the pair. Initially because I do subscribe to the shallow notion that the first girl whom the hero shows interest in should end up together with him. But mostly because, as I continued to watch the show, their personalities truly complement each other, and because they've been friends a long time, they understand each other's flaws and abilities best. Read more about Danny and Sam.
Now, the surprising thing is, I really am not a huge fan of best friends turning into lovers. I hated the fact that Kim Possible and Ron Stoppable of Disney's Kim Possible got together, because they were much better off as friends. Maybe because I sort of wanted to prove that a guy and a girl can maintain a platonic relationship and not have to develop romantic feelings for one another. However, for Danny and Sam, I really can see them going in that direction. :) Probably because it's been obvious to me that they have feelings for each other from the start, and it was only a matter of time. For another, their friendship doesn't seem to be affected at all when they took things to a different level -- if anything, their love in effect has been transformed and deepened.