I have a somewhat modified rating system. There are movies that suck; those are one star. There are mediocre movies; those get two stars. There are good movies; those get three stars. There are movies which you watch and suspect you'll watch again; those get four. And then, of course, there's the movies you watch for the first time -- and then, on the way home, still laughing, go to the store, buy, wake up your wife, and force her to watch, but of course she doesn't really get it, and is mostly irritated at you, but you don't regret it because man, it's really just that funny, and you skip work the next day and watch it a couple more times, and by the end of the week you and all of your buddies telling a waiter "I'll have a steak sandwich and... a steak sandwich" and giggling. Monty Python's "Holy Grail" is the, well, the grail shaped beacon of these movies; "A Fish Called Wanda", perhaps "There's Something About Mary." These are comedies with staying power; humor which uses more than shock and vulgarity, motivated by the lunacy of the human condition.
If you haven't seen "Fletch", well, frankly, I'm jealous. I'll never get to see it for the first time again, and there just aren't that many treasures like this out there.
And if you have seen it, you know you want to see it again, and you'll end up watching enough times to justify the cost, and, what the heck. Charge it to the Underhills.