Today it's the MacBook Neo unless you have a higher budget and want a nicer screen and more power. Then it's the MacBook Air, unless you do serious photography, video, audio, or development work then it's a MacBook Pro.
It's still a pretty simple, linear progression up the line.
Steve Jobs presided over an era where they were selling:
- A white plastic 13" MacBook
- An aluminum 13" MacBook
- 13", 15", and 17" Macbook Pro
- A high end 13" MacBook Air that thermally throttled and was more expensive than most of their other laptops