I remember laughing my ass off at "Borat" in the theatres. Haven't seen it since, and whereas part of the funniness, I think, was being surprised at what was coming, watching it again was delightful just to see Sacha Baron Cohen's barely masked delight when the people he encounters actually out-stupid Borat. By a lot. Some particular highlights in racism and homophobia include the old dude at the rodeo in Virginia, and, sadly, the fine young University of South Carolina students. It takes a lot of blithe dumbness to make Borat look like your straight man. However, some people can end up looking pretty good. I'm thinking of the driving instructor, and the kids in Atlanta. I also love the 1000% commitment of the film to creating this character, down to the menu options on the DVD.
In terms of watching this before you die, I'd say yes, if only because trapping people in "gotcha" moments on film, whether for good (the infamous "macaca" moment, the guy who posed as a billionaire donor to get Scott Walker on the phone) or ill (the collected works of James O'Keefe) have become part of what's expected in political and pop cultural discourse. I'm not sure it's a totally rigorous commentary/critique on American mores, just because the situations, whether partially scripted or not (and I think some of them had to be), and story are so highly choreographed, if not outright contrived. That's not a bad thing, just makes it more a sociological study of humor rather than American culture, I think. Of course, we all know sociology isn't my strong suit!
I would like to conclude this post with an open proposal to Sacha Baron Cohen. Of marriage. Any time, any place, SBC.