There are so many classic Jane moments to choose from, but if I had to pick just one, it would have to be when she's dating James, and talking about how hard it is to love someone who's in love with God. How you can't just put on a long beard and shout, "I am the lord, your god, take me now"...
Of course, being Jane, she follows that up with, "I've never seen him so cross".

Rob