It's not about the story. It's about the fun. A lot of people will say the plot of this movie was lame, predictable and dumb and yeah, they're right. But this kind of movie isn't about a brilliant plot. It's about interesting characters and silly gags and parodying those more serious types of movies. There are some funny lines, sight gags and slapstick, some cute girls, the bad guys get what's coming to them and the good guys win. Throw in some surprising celebrity cameos (some of which you might not catch until the credits roll) and a great soundtrack that mixes old and new songs and that's what I call entertainment.
The cast is noteworthy too. DJ Qualls, of course, Zooey Deschanel (the chick from Elf), Eddie Griffin, Lyle Lovett, Jerod Mixon, Parry Shen, Matt Gogin etc. did a fine job. If you can watch a movie without being hypercritical about how "bad" it is, then get this, sit back a have some laughs