I'm tempted to read it again and see what I think of the ending now; I'll probably have a fairly different opinion on it from when I was thirteen.

Yeah, quite possibly. And hey, it's worth rereading once every few years. ;-)

I think she did love him, it just...well, not in that crazy, fiery, impassioned way she loved Heathcliff.

Yup, I agree. Though we're also told her love for Linton is more transient and, obviously, less powerful than her love for Heathcliff. The latter is very literally her soul mate, after all.

Though to be honest I always felt that Heathcliff was the more passionate one; Cathy seemed to view her love for him as more natural and part of her, if that makes sense.

Hmmm... I'd never really thought of it like that. I think Heathcliff does act more as a result of his love, while she feels it just as much. She just seems to accept it more. I think she shows her passion more than enough when she goes nuts from being torn between Linton and Heathcliff, though.

They're all completely 3D, complex people with a whole rainbow of attributes, both good and bad, woven into them.

Emily Bronte was ahead of her time. :D