Honorable mentions should be given to It's Dark and Hell Is Hot, along with Get Rich or Die Trying. Both reintroduced that street sh!t to the masses at times when everything was super commercialized. I think Jay even said of 50 at one point that "he DMX'd the game."
50 had all kinds of rappers naming names and beefing left and right. Hip Hop turned into WWE based on him and G-Unit's exploits. Had folks on this very message board and the board that preceded it talking about rappers needing to get with other rappers to tag team the competition. It was like World War 2 with the Axis and the Allies. Meanwhile for the most part it really was just music. That's 50 though. When you think about it, it wasn't until 50's beefs that you started hearing the very word "beef" outside of Hip Hop music. Katy Perry and Taylor Swift would have simply had issues that needed resolved if they grew up in an era that didn't include 50 as an influence. Nowadays everybody has a "beef" with someone.
Had all kinds of folks rocking doo rags, fitteds, and brought back special emphasis on chains IMO too with that spinning G-unit chain. Had labels looking for the next best artist who really was in the streets too. Remember Gravy had someone shoot him the azz and then he went and did an interview right afterwards? Blame that on 50.