Warning: This is going to be skewed to the genres formulated in the late 80's. Being Thrash Metal onwards. Generally speaking, I enjoy music where meaning is conveyed through narrative song construction, where melody and harmony intertwined progress through a structure not dissimilar to a poem or a novel. I find this is done best in modern music in these later genres of metal. I don't much care for most vocal-centric music. If you can't stand 'growly' vocals, which act more as a device for rhythmic variation and not as the centerpiece of most 'underground' metal genres, you won't find much of interest in this thread. I would suggest trying to get over this aversion however, because the best of the music underlying these relatively unimportant vocals can be creative and dynamic to an extent not seen in most modern music.
#1: Supuration - The Cube. 1993.
This album features similarities to Voivod, but on top of having a joy for the unsettling and odd harmonic structure, Supuration develop startlingly singable melodies alongside the dissonant distortion clash pioneered by those mentioned Canadian geniuses. For the rhythmic guitar, slower tempos and ponderous deep chords interlock with mid tempo palm strumming. The melodic lead is versatile and intelligent, sometimes arpeggiating, sometimes singing. These two interact in unpredictable ways, but the amount of balance achieved is staggering through two seemingly non-connected forms.
I believe this album uses the concept of musical space to great effect, something rarely seen in metal. Chords lengthen and relax after a series of more standard metal rhythmic picking, sometimes letting melodic lines flow over a suddenly effective simplistic rhythmic space. The lead is quite capable of doing this in response to the rhythmic guitar chugging as well. Even the drums often get in on this diversifying act, shifting time keeping from polyrhythm to monorhythm often (a simple eighth note clock ticking ride or hihat). This shifting space leads to is a changing and diverse focus on various instruments, melodies, and rhythms rarely seen outside of classical music. Sometimes open and cavernous, to the point of Pink Floydisms. Sometimes structured and rhythmic (although never fast and chaotic like thrash metal). In and out of this structure the melody flows with grace, intelligence, and subtlety. In the same way Supuration use space, they also use the harmonious and the dissonant...resulting in an album that is incredibly balanced, diverse and interconnected.
They call it progressive death metal, but it's a genreless album in my opinion, and for the better. Give it a spin!