Fuses do NOT make ANY difference to the sound. Anyone not agreeing suffers from the audiophool syndrome. There will be scandalous resistance to this comment but just take my word for it.
Use UL approved, slow blow properly rated fuses which came with your system originally.
If you are still popping them, there may be a fault in your system.
Remember, fuses pop for a reason (typically to avoid a fire). Do not do anything weird (like installing higher rated snake oil fuses) to give the insurance companies any excuse not to pay for your burned down house.