I am a fan of the films about profound loneliness and existential angst. I think Lost in Translation crossed the line from good to brilliant, and I don't think that about all that many movies. If you aren't a fan of angst cinema, however, then probably you should just skip this whole review, 'cuz it's going to come off as a bit bullshitty.
That being disclaimed, Broken Flowers is a grade-A fabulous film. It deals with some of the same concepts (regret, longing, loneliness) as a lot of Bill Murray's more recent work (Lost in Translation, Rushmore), and the character he plays is uncomfortably similar to his characters in those films, but it's still worth watching. I think one reason that it is worth watching Murray play essentially the same character is the (some might say overdone) focus on travel in Broken Flowers the film. While Rushmore dealt with a hometown hero, and Lost in Translation dealt with an anonimity and discomfort of a completely foreign culture, Broken Flowers deals with the loneliness of travel, which is a different monster and enough of a change to keep you interested, even if you have seen Rushmore and Lost in Translation several times each.
Another thing that kicks this movie up several notches are the stellar performances by the women in it. First off, how great is it to see any film with several (hawt!) actresses over 40 in it? Sad that I have to be so excited about the novelty of that, but there it is. Secondly, these women are GREAT. My favorite is Tilda Swenson's (remember her for being the only palatable part of Constantine?) character, Penny. What I particularly liked about Penny was that she was the only character who acknowledged the invasiveness and amazing sense of entitlement in showing up at someone's house when you haven't seen her in 20 years, and she acknowledged it by getting good and pissed off. She's only in one short scene, but it's a great scene. (Sidenote: If her lughead husband hadn't gone on to beat Bill Murray up, it would have been a better scene, but it was good to see a cameo by Chris Bauer, who I really miss from The Wire.)
The other female performances are nearly as good as Swenson's. Sharon Stone is lovely (and surprisingly funny) as single-mom-and-closet-organizer Laura, and Jessica Lange is fabulous, as always, as animal communicator Carmen. The other real gem, though, is frustrated Stepford wife/real estate agent Dora, played by Frances Conroy. Her performance was almost enough to make me wish I'd watched Six Feet Under (but not quite).
The smaller female roles are filled by younger women, and they are not as perfectly cast, but are still mostly good. While I wasn't particularly impressed with Chloe Sevigny's turn as Carmen's assistant, or with Julie Delphy's portrayal of Sherry, the girlfriend who leaves Don at the beginning of the film, I quite liked Alexis Dziena as Laura's oversexed teenage daughter, Lolita (yeah), and will watch for her in other things.
Another thing that sets this film apart is the fact that it is really funny. In retrospect, I can't tell you what, specifically, about it is funny, but the theater I saw it in cracked up several times, and I cracked right up with them. I think it's one of those films that is funny without smashing you over the head with it, which is appreciated, especially in the summer.
Giving a plot synopsis would bore me, and probably you as well, but if you want to read one, Roger Ebert's (jerk) is here.