I don't have a "favourite."I think several of them are plausible, but they have to be analysed from the bottom up and not the top down first. There are lies and conspiracies on the local level. You first see them in local police corruption, municipal oligarchy, small-time fraud, etc. Most of the conspiracies going on are not quite so bizarre as mind-control, genocide, or one world government - and not organised by one central conspiracy group, more localised corruption and negligence. Then you have larger conspiracies which can be attributed to profiteering and psychopathy, but which are subordinate to objectives.
Ruling elites do have goals, long-term objectives, and desires beyond winning the next election or maximising profit. The "official" narrative should always be second-guessed and scrutinised into context. This is not so much something most people don't know already. Yet let's not kid ourselves that the elite always have either selfish or benign objectives, or that deceit can't happen on a massive scale. Think about the WMD in Iraq scandal. It's no longer a stretch to say that it was a complete fabrication, yet people were accused of being batshit insane when they called it out for its bullshit.
I for one suspect that weapons scientist David Kelly [http://en.wikipedia.org/wiki/David_Kelly_(weapons_expert)] was murdered by government order after turning whistleblower. The official story is dodgy, and several doctors have called out the findings of the dodgy Hutton "Inquiry". There was no And it is linked to the fabricated WMD dossier.
http://www.globalresearch.ca/was-david-kelly-murdered-on-the-orders-of-the-british-government/16434
Though I hate to upset anyone who thinks that "liberal democracy" protects from tyranny and persecution, even democratically elected governments assassinate their own citizens sometimes.