I was stunned when I heard "I'm Broken". I had seen Pantera open for Skid Row a couple years earlier on the "Vulgar Display of Power" tour at the Seattle Center Arena and they stole the show. They lived up to the name "Cowboys from Hell".
When I was in middle school, a kid in my class said he was a cousin of the guys in Pantera (And I'd took notice of the ads for their band playing at local clubs on TV so I figured they knew what they were doing) and I was so impressed by that Arena show that I had to check and found out that indeed, Pantera was the same band from Dallas-Fort Worth.
When "I'm Broken" hit the air, I was stunned. I had heard nothing like it before. Erased was the upper-range vocal intentions influenced by the English metal invasion (Judas Priest, Iron Maiden, Def Leppard) Instead, I heard the lower range of a guy who had been drinking whiskey on a bayou and was backed by master lever musicians cranking out a beat that is not easily attempted. And I saw that show at the Arena.
On the 'Vulgar Display of Power' tour, Phil encouraged everyone to 'smoke weed' at the top of his voice with a microphone at the end of the set.
On the "Far Beyond Driven" tour, the band played 'Planet Caravan' which counterpointed the aggression of the "Vulgar Display of Power" tour.
Personally, "Vulgar Display of Power" got me through college. The lyric 'Speak the truth about me: determined.' is my touchstone when life gets tough.