I think there's a sliver of truth to many conspiracy theories.
It may not be a sliver that supports it though.
As such I don't spend much time/energy on them.
My thoughts:
JFK - second shooter
Moon landing - happened
Alien abductions - complete fabrications
Secret Societies - exist, but likely focused on financial gain rather than world government
Governments spread disease - no
Big pharma more focused on treatments than cures - yes
Illuminati - See "secret societies"
While I'd hate to think that the Government was in any way a part of 9/11, I do admit that anytime I see pictures of plane crashes I see massive debris fields. I think of my own vision of a clean hole in the side of the pentagon and a few scraps on the lawn. I don't think the government was involved in the towers, but I wouldn't be surprised to hear they piggybacked the pentagon attack for personal interests.