I suppose I just had to post after reading another comment that called this film "bloated and pretentious", not to mention FAR inferior to Ronin(!). The only reason the two films can be compared is because they both have "wrong way down the freeway" car chases, so that tells you a little something about the depth of that reviewer's viewing.
Anyway, To Live and Die In L.A. is simply a great, great film. I personally think it's Friedkin's finest work, a completely unpredictable, brutal, and remarkably acted masterpiece. Friedkin is crafty here. He starts it off in a most mundane fashion: a cop hunting down the bad guy who offed his partner. And, well, that is basically the whole story. But what happens in this story is just beautiful. The twists in the plot come at you out of nowhere, and the way Friedkin toys with audience expectations is terrific. William L. Peterson's Secret Service agent is presented as a risk-taking hotshot at first, the kind we see in dozens of formula films. But we soon realize his hotshot behavior is a symptom of his psychosis. He's willing to risk the lives of his partner and innocent people in order to get his revenge.
The ending of this film is particularly great, and it ends with a nice punch as Friedkin kind of lets us know who he thinks the real villain is. The final image at the end of the credits provides the answer to that I think. Also, Friedkin's insistence on making L.A. look like the hell he believes it to be is a nice touch. And, as one character finds out, there's no escape from this hell. Major love to this flick.