Embarrasing to admit but I own many of the lenses discussed here (TE90, Hex 90, Rokkor 90, Elmar 90, Nikkor 85 and J9). Don't know how or why I ended up with so many. Regardless, the Hex 90 is the one that stays in my regular carry bag. Fast throw, great imaging, built in hood, almost flare proof, perfect match for my M6, it's just an absolutely great all around lens. Yeah, I enjoy the Nikkor 85 with my M3 when I have the time to deal with the slow focus throw (and man is it incredibly sharp). And the Rokkor 90 is a nice, low cost compliment to my CL travel kit (which is nice in that I don't have to worry about it when I'm traveling). And the Elmar 90 is just plain fun when I want to play old-school but it does need a hood since it's so flare prone. And my J9 even works well but is redundant with my Nikkor 85 since they're both Sonnar design lenses. The TE90 was my regular carry lens until I got the Hex 90 which is the one I'd keep if I could only keep one of them.
-Randy