Every Iced Earth album
Metallica's first four albums
Nightwish's Once and Wishmaster albums
Children of Bodom's Hatebreeder and Follow the Reaper albums
Soilwork's Natural Born Chaos and Stabbing the Drama
In Flame's Clayman
Amon Amarth's With Oden on Our Side and Fate of Norns
Iron Maiden's Number of the Beast, Piece of Mind, and Powerslave albums
Kamelot's The Black Halo
Pantera's Cowboys from Hell and Vulgar Diplay of Power

And a bunch of others. Of course, music is my passion, so there are probably more albums that I "can't live without" than most people.

To all the CD bashers, I still buy CDs. I only buy my music (I understand what it's like to be struggling musician, and the vast majority of musicians aren't on the radio and are struggling), and I don't like dl-ing from iTunes and the like because I like getting the book, etc. that comes with a CD (I'm a collector of sorts). Also, I just like having physical copies of my media in case my HDD fails, or so that I can loan an album to a friend, in addition to many other reason. The same goes for movies and games as well.

 Did you know that The Postal Service is releasing their next CD on Christmas? I'm so excited, and I just can't hide it. I'm about to loose control and I think I like it.

Metropolis Part 2 - Scenes from a Memory
Both Liquid Tension Experiment albums
Movie and videogame soundtracks in general.
Beethoven and later classical music in general (not that big of a fan of Bach and Mozart stuff)

I dunno, there's so much music that I really like.