The popularity of MMA currently owes a lot to that fight. The codification of the rules which enabled States to sanction events paved the way for the first Ultimate Fighter reality show. Getting MMA onto "free" TV, even if it was Spike, really opened up the sport to a lot of viewers. And the war between these two guys made thousands of young men (and some women) say to themselves, "Man. I want to do THAT!"
We're seeing the fruits of that fight now, with elite level fighters who wandered into a gym specifically because they saw that fight.
What's interesting is that, as fans, we allege to hate the decisions and love the finish. Whether it's a TKO or a slick submission, that's what we consider the most fun. But how many people talk about the 2:47 TKO in the OTHER final bout that night? Diego Sanchez fought Kenny Florian and knocked him out in the first round. Who talks about that fight? How many people even remember that Diego Sanchez is technical the first TUF champion because his fight was earlier on the card?