Possibly your best yet in terms of humour.
Actually, make that DEFINITELY your best yet in terms of humour.
It possibly doesn't have /quite/ the same re-watchability value (I know that's not a word but...) as the other 'normal' episodes, but...
The first time I saw it, I really cracked up at the songs.
And you do so much more than just play amusing songs. You make little changes and basically do a pastiche of your own cartoon. That's why it's so hilarious. I could go on about all the bits I liked, but I won't spoil anything for others.
The little bits beyond the basic joke of the songs means that this is definitely worth watching at least twice, and it's great how it doesn't take itself too seriously.
However, whilst you obviously know best (it's your baby and everything), I feel that this is definitely funnier after you have seen the 'normal' episodes.
For this reason, you might want to consider making the original #1 the first episode again on the series' page.
Apart from that, I have next to no criticisms. I couldn't decide between a 10 and a 9, and I thought about this for a long time.
The only criticism I could make is that the word 'losly' (loosely) is mispelt the 2nd time it comes up in the credits.
And, looking at the past reviews, you're probably disappointed that I'm going to rate this higher than YTown Public (normal series), but I seriously find this funny.
But, if you made another one, it wouldn't be that funny any more.
(It's a 1-off joke-type thing I think)
The normal series is better in terms of it's story though, and works really well as a series. But this made me laugh more than anything else I'd ever seen on NG.
Possibly also more than anything I'd ever seen on TV!
I'll give you a 10, but in good faith that you change the spelling of that 1 word in the credits.