1. The Downward Spiral - The layering of sounds in this album is so dense, yet every song has a strong melodic core. Absolute masterpiece of composition. Furthermore, every song is just great. Every single one. While the album's concept doesn't resonate as strongly with me as The Fragile, Broken or With Teeth, song-by-song I don't think it has an equal among NIN or pretty much anything else.
2. Year Zero - Strongly conveyed concept, lots of seriously enjoyable electronic noise. My only problem with Year Zero is the samey way the tracks start: they mostly solo the rhythm for a few seconds (which continues unmodified throughout much of the song) before vocals enter. Other than that, I think it's a great sound and a great album.
3. Broken - Another brilliantly realised concept, with nihilism and sexuality referring to oppressive domination by the record label. Being born in the TDS era the layered production and inventive composition are top-notch, and the industrial metal style yields some scorching material. I think it starts to flag later on - I'm not fond of Gave Up or Suck - and it doesn't have one of Trent's typically perfect closing tracks, so it stays behind Year Zero, despite containing some of my favourite NIN songs.
4. The Fragile - This is actually my favourite period for NIN material - I absolutely adore the new songs on Still and Things Falling Apart, plus Deep, Perfect Drug and the menu music for And All That Could Have Been. But the album itself has never entirely clicked with me, which is why I always play it with the additional period material spliced into the playlist (at which point it does become an absolutely incredible experience, but we're rating the vanilla albums here). I find the blaring layered guitars rather grating, and they dominate the album to such a degree that the emotional tone to the story rarely sees the light of day. In my opinion.
5. The Slip - I've had a bit of a love/hate relationship with The Slip, but after making a few minor modifications I'm entirely happy with it. Love Letting You and The Four Of Us Are Dying.
6. With Teeth - Another love/hater... I think the album's narrative, and the themes it draws upon, are amazing. All the songs have at least the germ of brilliance, but with very few exceptions I think they fail to realise their full potential - partly because of the reliance on comparatively conventional-sounding guitars, but mostly because of the ridiculously prominent and heavy yet frequently unimaginative drumming.
7. Quake OST - Not the most dynamic collection of music, but it works so well as ambient music, and it's enormously evocative. Like Antichrist Superstar, it almost feels like a tangent of the Downward Spiral concept. Some of the later tracks are just plain boring, but that's made up for with a rare bit of genuine industrial (and a bloody awesome bit, too) as the opening track.
8. Pretty Hate Machine - Not enormously keen on this one... I like how accessible it is, and there are some great songs (I particularly love Sin). But the Purest Feeling collection seems to have far more soul in its simplistic composition than the finished album does - it's like the army of producers marched through and tore out its heart. It doesn't feel like a cohesive or emotive set of music to me. If I'm in an '80s mood, though, it's a fun listen.
9. Ghosts I-IV - None of the tracks are bad, but collectively I find Ghosts a bit hard to listen to, and I get seriously bored if I try listening to the whole collection in one setting. It's too invasive for true ambient listening, but not gripping or evocative enough for primary music (which in my opinion The Social Network OST is, and GWTDT just about gets away with despite the gargantuan length). It makes effective computer game background music, though, which is how I normally use it.