I would give you some reputation for that one allison, but it says I have to spread around more, so I have to wait till someone does a nice post till I can give it to you again. Confusing stuff!
That's actually a pretty interesting thread samboo, although I think we had a similar one some time ago.
Anyway, I also think the older seasons are better than the new ones, for several reasons:
1) I liked it more when the boys were younger and had to deal with the kids vs. parents issue more, and with the whole childhood problems. That reminds you of your own childhood of course, which is always a funny thing.
2) There were the children of course, but there were also the grown-up parts from Lois and Hal, AND the teenager problems, represented by Francis. In the later seasons, they all are teenagers (more or less) or adults, which in fact changed the whole concept of the show, showing situations out of 3 points of views: mainly from the children, but also from the parents and from a teenagers views.
3) The better storylines. Yes, there were in fact better storylines. In Season 1 (and two), nearly every episode was uniqe and great. The Pilot, Red Dress, Bowling, Funeral, Rollerskates, Smunday were all amazing episodes from the beginning to the end. But when you look at the newer episodes, besides a few exceptions, they certainly all have great scenes in them, but they aren't perfect from the beginning to the end like the classic ones. This may be a matter of taste, but I guess I'm not the only one who thinks that way.
4) Furthermore, there happened to be some changes over the years, which you don't always have to agree with. For example, I think sending Dewey to the Buseys was the right thing, but it certainly would have been better that no one besides himself and the viewers knew that he was a genious. (It would be so much funnier if everyone treated him like he was "handicapped", but that's only a thought... Same with his piano playing and general music skills. Would be much funnier if he would win all the prizes without telling the family.) - To say it in other words: I miss the weird Dewey.
Same with Malcolm: Most people probably don't agree with what he turned into - a desperate whiny complaining teenager.
The list goes on, some didn't like Alaska or to the Ranch, some didn't like Reese becoming sensitive etc etc.
Those changes may in fact seem tiny when you watch an episode, but how can you like a storyline with Malcolm, if you can't stand his bitching anymore? Or a storyline with Dewey, when there is nothing special and weird about him anymore? That in fact may affect your judging and make the newer episodes seem slightly less excellent as they may be if you wouldn't know the others. But I am drifting to some strange point now so I simply stop talking.
It's of course a matter of taste if you like what MitM turned into. But I have to say that I liked the classic ones a tiny little bit better, because of the reasons above.
I hope the final season will be an end that lives up to the show as whole. That would maybe change my opinion.