Out of the powders you listed, I went with Unique. I've been loading that in a .44 Magnum for a long time now. If the question had been for a .38, I'd have picked BE.

Last year, when the powder shortage was near its worst, I found some 800X. I had never tried it, but loaded up some 200 gr. DEWC from Rim Rock Bullets, at a really modest velocity. I got such good results 800X is now my "target load powder" for the .44 Mag, and I've bought more since.