Here are some kitchen sink honorable mentions. Tried to pick out a few that get little to no play here.
Helmet - Meantime - pretty good groove metal here, also serves as proto-nu-metal, but is also considered one of the founding albums of post-metal.
Primus - Sailing the Seas of Cheese - quirky, experimental, funky (and funny) metal.
3 - The End Is Begun - A lot of you know this one. This is a very diverse album, as is most of their music.