Do you want to listen high quality Grindcore? I recommend you
Napalm Death: The fathers of Grindcore, everything started with Scum and From Enslavement To Obliteration (arguably the best Grindcore release ever) Their last disc, Order of the Leech, is really amazing but it is Death with Grindcore influences
Terrorizer: The Gods of the ultratechnical Grindcore. World Downfall, their only disc, is a Masterpiece in the history of music.
Nasum: The best Grindcore band of the last times, these Swedish guys are really the new Gods of the genre. They can play very fast but at the same time very technically. All their discs have excellent productions: Inhale/Exhale, Human 2.0, Helvete.
Agathocles: Legendary band from Belgium with very catchy and furious sounds. They call their style Mincecore: Grindcore with influences of Hardcore, Punk, Crust, and even Jazz. Their best releases are: Razor Sharp Daggers, Humarrogance, Superiority Overdose.