http://www.autofish.net/clysm/games/seiklus/ Seiklus, a blissfull, Zen trip involving gem collection in a trippy, surreal world.
http://www.gamehippo.com/category/focus_title_1.shtml Jumper: Redux, a tough jumping/puzzle game
http://www.harveycartel.org/metanet/downloads.html N - puzzle based platformer, very difficult. Amazingly developed physics engine.
http://www.amanitadesign.com/samorost/ Samorost, a flash game in the vein of the Neverhood
http://www.lincolnsoft.com/games/all/ Wow. What the crap. Amazing.
Those are all I can find right now, if anyone has anything, feel free to post.
Anyone got any good 2d platformers that don't involve jumping and collecting?