One of my (very few!) beefs with Knocked Up was that it didn't seem like Allison (Katherine Heigl) and Ben (Seth Rogen) were really all that into each other.
Cinematical (by way of Hollywood Elsewhere) has put things a little more bluntly: Would someone who looks like Allison actually get with someone who looks like Ben? Allison's character is not shallow or judgmental, but what she actually likes about Ben is unclear. And if we're going on looks alone, well, her sexiness factor is simply higher than his.
So, what about you?