Limiting it to just five sucks. I picked these just because most were a major part of my youth so there's some nostalgia influencing it. Not in any order:
Metallica- Kill 'Em All (sometimes I prefer Master of Puppets)
Soundgarden- Louder Than Love or Badmoterfinger, I can't decide.
Alice In Chains- Dirt
Nine Inch Nails- The Downward Spiral
Pearl Jam- Ten (sometimes I prefer Vs,)
And honorable mentions:
AC/DC- Dirty Deeds Done Dirt Cheap
Queen- News Of The World
Radiohead- Kid A
Tool- Lateralus
Temple Of The Dog
Pantera- Vulgar Display of Power (Lately I'm liking Cowboys from Hell more)
Metallica- Garage Inc.
Chris Cornell- Euphoria Morning