Some very funny Inception trailer mashups: http://insidemovies.moviefone.com/2010/07/29/inception-mash-ups-are-out-of-control-our-10-favorites/?sms_ss=email
Don’t worry, no spoilers that I noticed.
The Simpsons one wins. It is perfect. Everything about it makes sense as a dream world, especially the sinkhole as the ‘dream is collapsing’. The use of Bart is great, and so is the line at the end.