The first 30 minutes are hilarious and the dialogue is perfect. The reason I don't write a lot of fiction is because I feel like I can't write good dialogue. But Michael Arndt can, and it shows throughout the entire movie. The wit continues until the very funny end.
When you watch the movie, you are reassured that every family has its problems (yours included), that friendship is often found in unlikely scenarios and combinations, and that even if all we have is today, well, maybe we can make the most of it, and well, maybe it won't be that bad.
Go see it now. Walk, run, or push your van to the theater.