I know you don't mean to offend me but does it REALLY matter that i've never seen the first 3 indy films and gave Scary Movie 4 & Meet the Spartans a 4/5 rating?!
Just because i have different tastes than you doesn't mean i have to look at my purpose in life, there's more to life than movies you know....
It kinda does. First of all, the Indiana Jones trilogy are classics (or if you want to get picky,
Raiders is the most classic) and if you're going to appreciate adventure movies at all, then at the very least you need to have seen the Indiana Jones movies in order to truly form an opinion. Who knows, maybe what you consider great action movies now will probably be considered inferior once you take in a great film like
Raiders.
As for the whole
Scary Movie 4/Meet the Spartans thing - I get the impression that you haven't really been exposed to a lot of great comedy over the course of your life either. Granted, I haven't seen either film but that's mainly because they both look like the kind of braindead parody films that the American film industry churns out because they either cannot be bothered to produce anything particularly original in nature. In other words, something to be avoided.
Unless you can lay claim to having seen classic comedies like
Monty Python and the Holy Grail or
Airplane!, your opinion can merely be written off as inexperience. However, if you've seen other such films and still prefer
Meet the Spartans, well, I guess you've earned the right to your opinion.