The Big Chill is a movie that kind of makes me grind my teeth at the boomer generation, but I will cop that it's sort of a historically important movie, boomers in the Reagan era sniffing their own bungholes. I guess you should see it once.
Body Heat is also an update of the 40s, obvs. Kasdan was better known for his Big Chill type stuff than his 40s updates (and duh, he wrote that Spielberg/Lucas stuff.) Acclaimed "adult" dramas that you don't hear much about anymore--Grand Canyon, The Accidental Tourist, stuff like that. I don't know how much new legacy he got for writing the script for what is now the highest grossing movie of all time, but whatevs.
Hey, Wyatt Earp -- we've discussed that, right? I've never sat down and watched it from beginning to end but from various TV airings and my mom watching it a few times on VHS I feel like I could put it together from memory...it was supposed to be a big hit in 1994 but really wasn't. Remember this is when the press were all up Kevin Costner's ass about what a falling star he was.