I'll throw in another big vote for Yokozuna. I had factory Ultegra and Jagwire cables at one point before settling on the Yokozuna cable set so solve my poor shifting feel. They are simply amazing and there was so much less drag and a far better shifter feel than any of the others with my 6700 stuff. treefortbikes.com has them for just over $40 including brake and derailleur cables.

Two things: they're heavy, and if you have Shimano ferrule-less brakes (the ones that you just slip the cable into the caliper) they do not fit by default. I had to file down the Yokozuna cable ferules to make them fit inside.

I will not go with anything else anymore. I'm currently waiting for the derailleur cable set along with my Red shifters actually.