The broadest FF programe

What is everyone's opinion of the broadest ff programe for a leisure traveler?

I am signed up to CO's which as well as the skyteam partners/soon to be star alliance partners has quite a few other earning partners such as EVA or VS. This got me thinking, if you could only be part of one FF programme - which one has the broadest spec?

[Scrooge]

AA's, they can get me to just about anywhere, though as I type this maybe DL's for the same reason .

Great question