I don't know about everybody else, but the concept of a man having a baby in itself was beyond hilarious to me at first. Since Danny DeVito is one of the main stars, I knew the movie had a great chance of being an effective comedy. To say the least, "Junior" IS hilarious. When you see Arnold Scwarzenegger pregnant and performing some of the antics such as pretending to be a woman and trying to hide the fact that he's pregnant, if you have a sense of humor, then I guarantee that you will bust out laughing!
If you like comedy movies, especially ones that are entirely original, you've gotta at least rent "Junior." But I recommend for all comedy fans to purchase the movie because it's more than worth it!! NOTE: That was my Amazon review from the year 2001. I don't remember it as fondly now, but still funny.
In the end, even if you just laugh at Ahnold delivering ridiculous lines ridiculously ("mayh bohddy... mayh choizcze!"), it's something to watch once. Just never tell anyone... (oops).