Ok, I think it is fair to say that the Scary Movie films are not to be taken seriously, that they do require a few mates and a few beers to enjoy and that the odd number films are better than the even number film.
That said I must admit an odd relationship with the Scary Movie episodes. The first one was great, a slapstick gross out swipe at (amongst others) the Scream movies. The second one went to mainly spoof the 4 year old Haunting movie with Catherine Zeta Jones. This is where the Waynes brothers lost their way, though personally I have watched this a number of times and have a strange attachment to it.
The third film saved the franchise ?David Zucher/Pat Proft ?they of Airplane and Police Academy fame, changed the tone slightly but brought the franchise back with the visual joke laden installment finding itself spoofing a much more recent ‘Scay Movie’ ?The Ring.
The third installment follows this, spoofing (mainly) War Of The Worlds, The Grudge and Saw.
Bringing back Leslie Nielsen as the bufoon president was a good move and coupled with a load of other cameos (some bizarre) gives a lot to look out for, though I think it would help if I was more up on American day time TV (WHO is Dr Phil?) and American sports.
Needless to say the plot is a vague excuse to pack in as many visual gags and to spoof as many films as possible.
Overall the film is more of a Saturday night rental than a buy to keep.