If you're just replacing the wire, get an SRAM wire. If you're doing the housings, go with Yokozuna on the higher end, Jagwire on the lower. I haven't been able to do a back-to-back comparison, but my Force shifters with Yokozuna shift much smoother than Rival w/Jagwire. Not sure how relevant that is, but my understanding is that there isnt' much difference between Force, Rival and Apex save the materials on the brake/shift levers.