I'll add yet another take to this never-ending thread.
As an American car junkie, I saw MM1 when I was about 15 or 16. I was mesmerized, and happily puzzled by the cars (look like Fords, sound like Fords, but the steering wheel is on the wrong damn side!?). The action, photography, story all appealed to the pubescent teen. As an adult, I now appreciate the story and technical aspects more, and appreciate the film at greater length knowing how it came to be created.
Road Warrior aka MM2 I saw when it was released in the USA also, enjoyed it, thought it had a (arguably) better story than MM1 but gained a bit with the larger budget. Not quite as cool car-wise (what was with some of those vehicles?) but a worthy sequel for sure.
I only recently saw MM3. When it was released I knew, just knew it had become something different. I was right. Though it is a good story I'd offer that it has gone a bit too far, is a bit too cartoonish in it's presentation and the end chase sequence not markedly different than MM2. By now it is assumed all MM films will end with a head-on collison.

So, my summary as a Yank: MM1 is for car guys, MM2 is for action guys, MM3 is for science fiction guys. The reason we probably can't agree on all 3 is they appeal to different personalities.
BTW, I think the Aussie flavor of the films is essential, and probably the lack of it in MM3 is a detriment. On behalf of USA fans, I apologize for Tina Turner's existence.
