Porcupine Pie is pretty wacky, but I'd say it gets a pass because it sounds like he wrote it for his kids off the top of his head, and then decided to start playing it live, which is the sort of crazy think I love about Neil. (his writing a song about the movie E.T. is another example of this).
Cowboy Star is just awful all the way through. Though some people apparently like it...allmusic.com calls the song a "knockout"! HAHA! That whole Aaron Copeland section in the middle is SO BAD!