Star 80

Damn, how do you put things in italics? I think I've been using EZboard too long.

I obviously think it's worth owning, though the dvd is pan and scan. Out of the three films you mentioned, I'd say Star 80 is closer to Boogie Nights in that the two films are probably matched as the most feverishly atmospheric depction of the 1970s in the cinematography, costumes, art direction, and music.
Star 80 has a definite sense of humor in its approach, though its much darker in its attack. I used two sequences from the film in a presentation for a class on the art of film editing because I've always been strongly taken with how Fosse's formalism implicates itself in Dorothy Stratten's murder. Ultimately the narrative is about how Paul Snyder's murder (I'm spoiling nothing) ironically mirrors what the sex industry and fame machine was moving Dorothy towards. Pauline Kael too easily dismissed the film and criticized the overtly expressive sound design that equates playboy photographer camera clicks with gun shot sounds. I like the metaphor myself.
People also say that Mariel Hemingway's performance as Dorothy is unrealistically naive with regard to to what surrounds her, given that the real Dorothy Stratten was reportedly a good natured stoner complicite in her own exploitation, her naivite works in the same way as a female protagonist in a horror film; the film establishes an unbearbly intensifying tension because we are able to see what she cannot. It's best to think about Star 80 as an unintended critique of the Friday the 13th inspired slasher films that were big at the time of its release, the important difference is that Fosse's film opens up the genre to draw the logical conclusion to Hollywood's tendency to equate the violent murders of women

accidentally sent that too soon and I wrote far too much. Fosse's film asks uncomfortable questions about Hollywood's violent mysogyny is the basic point.
In its psycho-sexual subject matter and its formal approach, I'd compare it to Nicholas Roeg's Bad Timing more than any would other film.