Some of the following bands/albums are metallic, aggressive, and generally heavy in nature, but you did say any genre -
Fredrik Thordendal's Special Defects - Sol Niger Within
Meshuggah - Nothing / Chaosphere
Spastic Ink - Ink Compatible
Behold... the Arctopus - Nano-Nucleonic Cyborg Summoning
Dysrhythmia - Barriers and Passages
Collapsar - Collapsar
Upsilon Acrux - Volucris Avis Dirae-Arum
Sleeping People - Sleeping People
Yowie - Cryptooology
Ahleuchatistas - What You Will
Shining - Grindstone
Estradasphere - Buck Fever / Palace of Mirrors
Cab - 4
Planet X - Moonbabies / Live From Oz
Mats/Morgan Band - Live
Candiria - 300 Percent Density
Sikth - The Trees Are Dead & Dried Out, Wait For Something Wild / Death of a Dead Day
Pain of Salvation - Entropia / One Hour by the Concrete Lake / The Perfect Element I
Bubblemath - Such Fine Particles of the Universe
Intronaut - Void
Thinking Plague - In Extremis
Cynic - Focus
Atheist - Unquestionable Presence
Martyr - Warp Zone
Gorod - Leading Vision
Gordian Knot - Gordian Knot
At War With Self - Torn Between Dimensions
Canvas Solaris - Sublimation / Penumbra Diffuse
Aghora - Aghora
Atrox - Orgasm
Frantic Bleep - The Sense Apparatus
Ephel Duath - The Painter's Palette / Pain Necessary to Know (extremely annoying vocals, imo)
Koenjihyakkei - Angherr Shisspa
...should please anybody who gets off on odd meters, polymetrics, or most other kinds of rhythmic abnormalities.
edit: also, x2 on King Crimson and Bruford's Earthworks.