Due Date is a road movie in the purest form. Certain unfortunate comical events lead to Peter Highman (Robert Downey Jr.) and Ethan Tremblay (Zach Galifianakis) sharing a ride across from Atlanta to Los Angeles where Highman has his wife about to deliver their first baby. The movie is a big comedy of errors. It’s reminiscent of Steve Martin’s Planes Trains and Automobiles. It has shades of Hangover. It’s a buddy movie. It’s over the top and all out there. 
Robert Downey Jr’s mannerisms are all there. Zach Galifianakis pretty much plays a slightly sober version of his Hangover character. But, even after all this the movie is somewhat enjoyable. It has a certain charm to it and the comic moments are there albeit a few and far beyond. Then there are the cameos by the likes of Jamie Foxx, RZA, Danny McBride, and Juliette Lewis which are a welcome change. The dialogues at times are laugh out loud and that made a huge difference in me liking the film (quotes from the movie can be found at the end). 
What I do not like about the whole script is that it does not take any chances. There are numerous incidents and events where you expect that now there will be a break in the mold. Now, we are going to see something memorable. Now, the movie is going to jump over the edge. Unfortunately what happens is that as soon as the movie reaches an edge, it just puts itself into reverse gear and turns into a sob-fest. The tag line of the movie is “Leave your comfort zone”. Unfortunately that is the one thing the film does not do. 
So should you devote your precious time to watching this movie? Yes, but wait for the DVD to go on sale or better yet wait a few months so that it’s on TV for free. A perfect 3 starts out of 5. Quotes/Dialogue that when I now read and write are what really made the movie.
Peter Highman: I'm sorry we drank your father.
Ethan Tremblay: That's okay.
Peter Highman: Are you all right? Are you sure?
Ethan Tremblay: Yeah, there's plenty of him still in here. Darryl, he made three cups of coffee, I think there's about eight cups of my dad left in here.
Peter Highman: Great.
Ethan Tremblay: At least he tasted good.
Peter Highman: Not bad. Yeah, strong. It was uh...full flavored, robust blend.
Ethan Tremblay: He really enjoyed coffee and in the end he was enjoyed as coffee. Circle of life.
Peter Highman: Lion King. All that.
Ethan Tremblay: Holy Moses, it's like I'm traveling with a child!
Peter Highman: Have you used the restroom?
Ethan Tremblay: Good point, I need to take a pee-pee.
Ethan Tremblay: I got ninety friends on Facebook, twelve of them are pending, but I got ninety friends
