Really, the question is what mid-game policy tree offers the best opener +1. I usually have two points for policies in between finishing my opening tree and rationalism being available.
Consulates used to be the way to go but it seems worthless to me now. Cultural centers in Aesthetics could be useful (especially if it helps get UB's like Ceilidh Hall up, I'd imagine it does), Wagon trains (going wide or building a lot of roads en route to domination victims) or Merc army in Commerce seem decent situationally, and a few points in exploration might be useful for coastal empires.
If you built The Oracle or have an obscene amount of culture, you'll end up with three extra policies. In this case, Military Tradition in Honor, scholasticism in Patronage, and a bunch of other options open up.
Personally, I also really like a hybrid left side of liberty/tradition opener before Rationalism now that consulates isn't broken. This requires building the Oracle to consistently not delay Rationalism.