The problem with Weird Al is that he has so much more musical range and career longevity than most the artists he parodies. The tracks become perplexing when the original artists fade into obscurity.
and like all satire, you can't really enjoy it unless you've been forced to endure the source material.
I think that's why I like the style parodies better than the song parodies. You might forget specific songs, but whole sub-genres of music linger a bit longer.