I love the sense of growth in that you start playing without a frame of reference and move on to pulling off tricks and completing levels in ways you couldn't conceive before hand.

Never liked Halo. Too slow for me.

I love that they are so easy to get into, there is not a lot of story, cut-scene heavy sections or just a bunch of text bubbles. It's straight to the action. I love 2d platformers especially doing speed runs, that is pretty addictive. Like some of the videos from NSMBW, just running through a level never stoping that takes quite a lot of skill. Which is fun so you can master a level they are easy to get into but they take some time and effort to master.

What I love about them is the diversity  that can be found within them in terms of level design, theme, gameplay,physics etc. Just in one game, take for example Super Mario Galaxy the diversity of such things is amazing compared to other genres, But then compare this to other platformers like Sly,LBP,donkey kong country, Ratchet and the diversity is just so refreshing and all of such great quality in my opinion. 

This expresses the idea of "gaming in its purest form," well. It's similar to some racing games in that respect, that each race is different, as you play these games you constantly experiment, finding and discovering different ways to move through your own world

There's a good reason i thought games were stupid until i picked up Super Mario 64. Granted, my tastes have broadened vastly since then, but that core appeal is still there

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.

I love the jumping and the hitting and all the powerups and the stories and and and and

What Zucas and Rol said.

It seems that platforming really isn't your type of action, it's there, but you my friend can't taste it...

I agree platformers suck.  To much of this press button to make a charcter over a dangerous pit or enemy BORING where are the guns and super powers up in this genre? 

In fact it should be more like Infamous, because I don't like it when my characters aren't white middle class men like me, blue hedgehogs?  Gay.  

Platformers fix your shit.

The simplicity yet complexity the gameplay can posses at anytime