The Best Phono cable

The best I've heard so far (in MY system ;-) is the Purist. I have their middle-of-the-range Venustas (MSRP $1950) but there are even more expensive models like the Dominus and the new solid core Provectus (which I've not heard but sure would like to ;-).

Obviously, you'll need to try a few examples to discover which one(s) provide the sonics you want when combined with your cartridge and electronics. The following, along with Purist, are the best out there in my ever-so-humble opinion ;-)

Silver Breeze (by Silver Audio, one of the best at any price)
Golden Reference (Cardas)
Avondale II (by Siltech, expensive like Purist)
Music Groove 2 (Hovland)
.

There is no "best". It is all taste- and system-dependent.
If you live in the States, get in touch with the Cable Company. They have a loan system and will let you try out cables at home with your own system.
Nsgarch above has given you a good idea what to try out. Purist, Siltech and the expensive Stealth cables ( but not their dedicated phono cable) would also be on the top of my list to try out first.

Chris, I would also suggest that you try the Synergistic Research Magnetic Tricon phono cable. Some time ago I was in the market for a better phono cable and tried several from the Cable Co., namely the SR Tricon, The Hovland Music Groove 2, and the Cardas and ended up much preferring the SR. Michael Fremer just several months ago compared five phono cables and two of which were the Tricon and the Hovland. You should take a look at the article.
As Detlof stated above, there is no best. It is all system synergy and the listener's particular taste.
Best of luck in your search.
Carter

I have used the Synergistic Research Tricon, Cardas Golden Reference, Furutech AG-12, Audio Horizons Dimension and Hovland Music Groove 2 tonearm cables. In my system, the one that has consistently given me the most textured, musical and enjoyable sound has been the Cardas Golden Reference.