I own all the three 35mm, 50mm and 85mm. All of them are good for portraits. 50mm seems pretty good for overall general portrait lens to me (head and shoulders down to the waist), the FOV is jus nice. 85mm is great for very tight frame (only the headshot), and u need to back out quite a distance to get the image.
In anyway, it still boils down to your preferences; and it is better go and try it out before buying.
Cheers!