Most significant metal releases

I like your choices, but I'd be interested in a brief explaination of why you feel they are significant.

I forgot to mention for the guitarist in me!!!!

racer x paul gilbert's welcome at a tender age
Scorpions/Uli that album started to gain recognition for Uli in the u.s, plus imo awesome work at that point.
Symphony X put romeo on the map and an awesome mix of prog/heavy shred imo.
Cacophony Friedman & Becker shred feats too
Ufo master Schenker ripping it up on one of the best live recordings ever not a weak song it was back in the 70's.
all of the ones i mentioned in no particular order
 
Man, that tempo and build-up to Bang-a-Gong is something, isn't it? I remember when I was a kid and my mom was jamming to some old T-Rex, I thought it was the coolest riff I had ever heard. To this day I don't think anyone's written something as groove-heavy and awesome as that. I know some of you will say Sabbath, but T-Rex is where it's at for classic rock, guys and gals.