NIN are odd for me, because I like a lot of their songs but haven't been able to get into a whole album. I have Pretty Hate Machine, Broken, The Downward Spiral, The Fragile and Year Zero (also downloaded The Slip and the first part of Ghosts) and TBH, Broken (which happenes to be the shortest) is probably my favourite overall, though TDS has a lot of good songs. Still, I want to get With Teeth and some of the remix albums.
Top 10 NIN songs for me would probably be
Physical (You're So)
March Of The Pigs
Big Man With A Gun
A Warm Place
Hurt
We're In This Together
Starfuckers, Inc.
God Given
Zero-Sum
Discipline
with various honourable mentions

I guess I'm kind of a "semi-fan" just now.