Here's one, complete with proof.
The sitting Secretary of State of the United States of America told a bald faced lie to the 9/11 Commission in order to deflect attention away from her and the Bush administration and NO ONE, not one single MSM source ever covered this. That's a conspiracy, and here's the proof.
http://dir.salon.com/story/opinion/feature/2004/03/25/condi/
http://www.americanprogress.org/issues/2004/04/b44918.html
"We had no idea that planes would be used as weapons."
MASCAL (Mass Casualty Drill depicts Pentagon as the site of an aircraft strike, 10 months prior to 9/11)
http://images.google.com/imgres?img...e+crash+drill+mascal&svnum=10&um=1&hl=en&sa=G
There's literally thousands more, I could give them to you one at a time or all at once, but the bottom line is that even something this obvious, this well documented and this well sourced will never reach the level of suitability for those who do not wish to believe in a conspiracy, so what exactly is the point?