I'd have to go with:
http://gamesblog.ugo.com/index.php/g...rtal_insanity/
Since I really <3 Portal. One of the finest games this year - probably this decade.
I see the screenshot for the Portal Flash Edition game, but did not see a link, so here it is if other CAGs are interested:
http://www.newgrounds.com/portal/view/404612