Hi,
The genuine Stanton D50 series of styli are your best bet, IF YOU CAN GET ONE. I just got one on eBay around March 2011, it is the "D50E Mk II"...pretty good for "audiophile" listening.
The only concern is being able to get one. eBay sellers come up with one of the genuine D50 series once in a rare while. My suspicion is that there is no longer one remaining in the world...and I tried three "after market" imitations with very poor results (poor tracking ability, and poor sound quality).
One alternative is getting one worn-out from the D50 series, provided the suspension and cantilever are fully functional. THEN, retip it with a Paratrace, or similar tip. I actually have one in new condition which is now fitted with a Paratrace...very good sound and tracking specimen.
Another alternative is a genuine Pickering replacement from
http://www.pickeringuk.com (you know Pickering and Stanton are brand names under the same umbrella corporation...sort of). I have one "DE" stylus with fine sound and good tracking ability. This is, also, a good candidate for tip replacement with a Paratrace from Expert Stylus and Cartridge Company...for a definitely obvious improvement on the sound.
My experience with a CANTILEVER replacement with a ruby was not succesful. A slight top treble resonance cropped up, which was mostly audible and not "natural" at all.
Good luck (you'll need it),
bauzace50
PS- I have one "after market" imitation from LP Gear (their name "DATE4"), which I don't like, and you can have for free (gratis, no charge whatsoever, NO strings attached) postpaid. Just write a Private Message, and I will get back to you.