Dear Jeraza, I presume you aren't asking about interconnect and speaker cable which costs thousands per met. If you want a inexpensive upgrade but one that will make a real difference try Kimber. Specifically I would use the PBJ for the analog interconnect and the 8TC for the Speaker cable. You can always improve on that with cable higher up the price ladder but the Kimber is a real steal particularly with the proces going crazy.
MC-1/Cinepro/B&W - Cable Recommendations
Relatively new to HT, need help with interconnects, digital cables for current system which consists of Lexicon MC-1 Pre-Pro, Cinepro 3K6 amp and B&W N803/HTM-1 (Front) and N805's (Rear). Currently using Monster Cables (cheap ones at that), but I obviously need to upgrade given the equipment. Been looking at Silver Audio "Hyacynth", HT Pro Silways etc... Any help would be appreciated