Hi
Like TMIT said it depends on sitch of whetever point of game I am in. I think for most of my games I spend biggest chunk of it in OR. Just cuz I like building bonus and getting out missionaries quicker either for culture or for happy boost or cuz I have shrine and want income boost, or cuz I want to get as many AP votes as I can. But sometimes FR can be nice for diplo purposes or science or culture or happy boost.
And I dont use it often but I will use pacifism at times in early or mid game if I am running tons of specialists. And ironically, I have found most times since if I do switch to Pacifism it is usually switching to it from OR and the drop in mainainance costs offset the unit costs to point where I can actually afford a BIGGER army than in OR hehe.
I guess about the ONLY one I pretty much never use is theo. If I feel I am that despserate for 2 xtra exp points per unit I will go vassalage otherwise I dont really find it worth the slowdown from anarchy to switch (and if I am spi or get a GA during war prep then I still prefer vassalage and dont really see need for BOTH when really one or other is all you need I think).
Kaytie