Any suggestions for similar movies?

I saw this movie for the first time not too long ago and I have to say this is one of the best movies I've ever seen. I'm wondering if anyone can suggest some movies in a similar vein. I've seen a good bit of noir from the 40s and 50s and I enjoy those films but I prefer this film's more modern take on the genre. I really enjoy the overall cynicism of this film and of course Elliott Gould's performance is amazing. Plus this has to be one of the coolest "LA" movies I've seen. The way they shoot the city is just perfect.
So any suggestions? A friend of mine suggested Chinatown, and while I think it's definitely a good movie it didn't really strike a nerve with me like the Long Goodbye did. I also heard that I should check out To Live and Die in L.A. but I haven't had a chance yet.
What do you all think?