Most likely to be finished:
Dean & 5 Witchy Women (ooh, I've already written a great bit with a Gaiman fangirl who likes to dress like Death and is a bit too innocent for her own good).
Dean Does Not Approve (5 Songs That Sam Listened To On the Radio to Dean's Disgust).
Because I want to have a Coldplay/40 Year Old Virgin joke ("you know how I know you're gay?) and write Sam and Dean reacting to Gwen Stefani's "Wind It Up." Besides, "...WTF is this crap?"
Oh, and Iris, Goo Goo Dolls. But Sam and Dean will both hate that shit. And Dean will bear a grudge against the ending of that Meg Ryan movie.