What is the best generic for desvenlafaxine/Pristiq?

I would say Lupin or Greenstone. I take greenstone but have heard good things about Lupin also. Really it depends on each person. What works for me, may not work for you. I believe manufacturers make a difference even though others would disagree.

My best answer is that the best generic for you is the one that works best for you because every person responds differently to medications. What works well for one person may not work at all for another so I wouldn't assume anything from what I read on the internet.
Personally, I've never seen any difference at all in the different generics I've taken over many years.
You won't probably have any problems either but if you do just ask your pharmacist to special order the one that's worked the best or have your doctor write a script for that specific generic.
Just for the record, in the last few months alone I've taken Par, Slate Run, and currently NorthStar. They've all worked equally well for me.