[Classic] Great Platformers

So that VVVVVV thread made me think about some of the fun platformers I've played over time, and all the ones I remember my friends playing but I never got the chance to. So, I figure, why not make a thread for those of us that have missed out on various gems here and there.

The only game I can say I've really played that wasn't super common was The Lost Levels from Mario All Stars. It was difficult as hell, but I managed to beat every level in that stupid game without using save states. I remember one particularly cruel part in one of the last stages where you had to make a blind full-speed jump and hope there wasn't a piranha plant waiting for you on the other side.

I remember a bunch of my friends playing N and getting a real kick out of it, though I never seemed to catch on because I failed so hard at wall-jumping (which is kinda ironic since it's a feature I wish more platformers put in ).

So what are some of your favorites? Or, even if it's not a favorite, what's out there that's at least worth playing for a little while?

Jam it back in, in the dark.

I think the Wikipedia page for Shatterhand has possibly the best set of references. Ever.

There's nowhere I can't reach.

Just gave Eversion a play over the last few days and I've got to say it was pretty neat. I had to read up on how to get to Level 8, but the ending was worth the frustration of that last level.

This thing is sticky, and I don't like it. I don't appreciate it.