There's all kinds of examples, but here's a couple that were done from last time in my room:
Most resistant last Thurs: "I Hate Myself For Loving You". First of all this song always goes over, and even if someone can't sing a note they can just get away chanting it and the room will fill in the blanks.
Least: "My Immortal."
(Edited because I was a little too catty eariler... just waking up.) I don't understand why women gravitate to this song. Maybe it's a catharsis thing. Anyway it's mostly a series of exposed, sustained, long high notes, and that's all I'm going to say this time.