On Harry Potter, I'd basically agree with everything that Lenny said. Add to that:
capes in multiple colors
Dobby (he's Gollum in my Tolkien project)
the troll
new hair pieces (not just for castle, but generally useful)
Hagrid's hair is great for dwarfs (along with the stubbies)
a few shields (Gryfindor, two snake designs), though it's imporssible to get these in usable numbers
a few of the torsos (Dumbledore, McGonnagal, Dobby, Hermione's blue sweater)
It is disappointing that the torsos are generally useless. Much better for castle torsos is the SW line. Looking at this page:
http://www.minimundo.de/inhalt/figuren/ ... ars456.htm
There are good torsos on the Emperor, emperor's guard, both Leias, three of the four Luke torsos, skiff Han (the one without the vest), and Bib Fortuna. I've also seen Leah Cardaci use C3PO's torso used as a Greek breastplate:
http://www.brickshelf.com/cgi-bin/gallery.cgi?i=172074
and the Gamorrean Guard (with a paint job) makes a good fantasy monster.
From episode 1:
http://www.minimundo.de/inhalt/figuren/ ... rWars1.htm
You have Darth Maul (repeat of the Emperor), Jar Jar, Anakin, and Qui Gon.
Finally from episode 2:
http://www.minimundo.de/inhalt/figuren/ ... rWars2.htm
there is Obi-Wan, Anakin, random Jedi guy, young Boba, and Dooku. I've also seen Brendan Smith use the Geonosian torso as a breastplate:
http://www.thebricktestament.com/the_wi ... 20_14.html
Of course stubbies from this and HP lines are good for hobbits, dwarves, other fantasy races.
Yoda's sculpted head would be useful, but to me it's just way to recognizable as Yoda, so it's use as a fantasy creature is distracting to me.
Bruce