Originally Posted by Unknown Soldier

Most of the late 1980s releases are probably the best place to start, quality wise though its not as good as the North American bands but its different. Kreator and Sodom are better than Destruction quality wise and the Kreator albums were produced by Scott Burns who has produced most of the best extreme metal acts at one time or another.

Destruction Eternal Devastation, Release From Agony, Cracked Brain and one of their later albums is probably their best The Least Successful Human Cannonball

Kreator Pleasure to Kill, Terrible Certainty, Extreme Aggression and Coma of Souls also Outcast is a great later album.

Sodom Persecution Mania, Agent Orange , Better of Dead and Tapping the Vein

For the record, German Power Metal bands are better than their thrash counterparts.