Potenza RE950s
Good on dry
Good in wet
Great straight line driving/stopping grip in snow. They're biggest problem is turning in the snow. Ice...well duh!
Between four sets of wheels and ten different tires on two FWD cars these are THE BEST all around tire I've used, hands down. They're probably going on the Audi once my current tires give out. I think if you had them siped they would do much better gripping through the turns in snow.
Second would be the Goodyear Eagle RS-A's(better dry, lesser wet, snow about the same)
Third would be Yokohama Aegis LS4's(decent dry, good wet, excellent snow-siped)
My .02