Oh yeah. Hardcore. And it's the most frustrating thing in the world to go through.
For me, the best thing I can do is actually change gears. Go write something else. Preferably not something serious. It can be silly, raunchy, something I don't have to try really hard to do. And sometimes that works.
The WORST thing I can do is sit down and think about the story. Obsessing over it and its finer details inevitably leads to brain clogs. Ask anyone with an overly analytical mind; the worst thing you can do is stew on something.
Edit: Forgot my number one way to get over writer's block: Movies! Go see a good movie, something that'll engage you! Geez, how could i have forgotten that?
For authors, Stephen King has grown on me. I used to be a big Jack London fan (have a complete collection of all his stories stashed away in my room). I try not to read too much, however, simply because the more I read, the more I imitate other author's styles, and that's kind of a pet peeve of mine.
For the second question, actually no. Well, there was this stupid little throw away thing I did for World of Warcraft that made it two chapters, choked and died on the drawing board, and never made it to the light of day. Most everything else i've done have been originals, not counting MLP fanfics.
For favorite episodes... The Royal Wedding. Hands down. Episode 100 is a close second, but the Royal Wedding really left a lasting impression on me, because it was the first time the series really demonstrated how freaking dark it could be, and epic, too.
For cartoons... Ed, Edd & Eddy. It got so bad that my father actually forbid me and my brother from watching it. Basically any cartoon on Cartoon Network during the early 2000s, so Ed, Edd & Eddy, Courage the Cowardly Dog, and a guilty pleasure, Totally Spies. Don't judge me, the show was awesome!
My opinion on the Chipmunks is that they have not aged gracefully and Hollywood REALLY needs to stop torturing my childhood.
As for witches, leave them for the Spanish Inquisition. No one expects them.