The "meeting the parents" premise has been done to death recently with Monster-in Law and Meet the Fockers being the most recent films. However, what the film lacks in originality, it makes it up with laughs. There were a lot of funny moments and the movie hardly ever got boring. However, most of the funny bits were used in the trailer and this makes the jokes a little less effective since they are already expected. Also, the repeat value of the movie is very low. It's worth watching once but that's pretty much it. I don't think that's a bad thing since most light comedies are like that.
I think the film works well because of the two leads. Both Bernie Mac and Ashton Kutcher give funny performances and they have nice chemistry together. Their scenes were the best and they never felt forced. Zoe Saldana also gives a good performance and she has come a long way from appearing in Crossroads. Most of the supporting actors are also funny including Judith Scott, who plays Bernie Mac's wife. Mike Epps also makes a cameo though it wasn't that good.
Kevin Rodney Sullivan directs and he only does an okay job. The first half of the film is pretty funny and the racial issues are handled lightly. During the second half, the film becomes all serious and it's kind of awkward. The director ditches the laughs for awhile and he approaches the issue in a mature manner. It kind of works but some of the serious scenes felt fake. It seemed like the actors were about to burst out laughing at any second and the film also got kind of dull. The ending was surprisingly strong though. The changes of tone in the film worked out okay but they weren't as effective as they could have been. In the end, Guess Who is worth a rental, nothing more though. Rating 7/10