That's interesting, because I loved it. As one fellow mentioned, Homer slapping his ass the whole time was enough to keep me laughing for most of it. As far as the whole 'doesn't make sense' argument ... well, a non sequitur ending (even if you noticed the green slime from Homer's ghost, the ending was still rather unexpected) seemed rather fitting for an episode telling three different stories. It's not like there was a continuous storyline to wrap up at that point, so why not dance around to "Ghostbusters"? :)
In any event, I'd give this episode a strong 'A' rating (not that anyone cares what my subjective grade is). The writers did a very good job on this one.
- JBL