The Super Mario 3D Land and World games are, in my opinion, some of the best examples of successful platforming design in the industry. They're varied, interesting and each idea never outstays its welcome. The games introduce new concepts at a blistering pace; there are more interesting concepts in the first few hours of these games than most titles have in their entire running time.
This video does an amazing job of breaking down the formula of why the level design in these games feels so good. It's built on a very simple, four-step process where a new idea is safely introduced, put into practice, subverted and then is given a conclusion so you can get to the flag.
Watch the video for examples, as well as the Japanese word for the four-panel comics and four-line poetry that served as the inspiration for this approach. If this doesn't make you want to replay these games, I'm not sure what will.