It depends on the game and the style. 2D platformers are some of my favorite genre because they focus on skill, timing and exploration. In 3D platforming, I also like the focus on exploration, but also because 3D platformers usually have a larger focus on gameplay than linear or story based 3D games.
Also, the reason I love platformers is generally because some of my favorite series fall under the category, Metroid, Mario, Kirby, Assassins Creed, Batman (NES and Arkham Asylum), etc.
Also, sometimes I just want to take a break from all the RPGs, FPS and RTS games and just play a pure action game. And platformers are usually the most action-focused with more depth than just a standard hack n slash.
Six upcoming games you should look into:
