If your Monster Cable changes the actual sound of the recording, I'd throw it away or demand a new one. It's copper, nothing else. Nothing about it should (or could really) change the sound. The point of a cable is to just get from point A to point B without coloring the sound. If your cable is coloring the sound, you're in trouble. If your cable can color the sound, then the longer the cable, the more it would color, and all sorts of problems would occur at longer cable runs.
If you do a true, 100% honest blind test, I guarantee you won't be able to tell the difference between a Monster and something like a Whirlwind or other cheaper brand. IMO, the only reason to buy Monster is because of the warrantee (which is amazing). For the price, though, you could get a much better construction on a cable - something like Mogami or Canari.
The stuff Monster puts on their packaging might be true in a lab with an oscilloscope, but nothing that the human ear can discern. If you can discern it, you are suffering the same problem that occurs when you turn an eq, hear a difference, then later come to find out the eq was never inline in the first place. Your brain wants to hear a difference, so it makes you hear one.
Same thing goes for those $300 IEC cables and such. It's power. As long as you're plugged into a conditioner, it's not going to change the sound of your gear.
So, in short, the thing you want in a cable is good construction and good noise reduction. In general, the quad-star type cables are the best at noise reduction, so I'd go with that. Mid-level Mogami or Canari does just fine. And, if you buy it bulk and solder it yourself, you can get a lot of it for cheap. Monster is fine too, just don't buy the holy-crap expensive stuff. Isn't worth it.
Check this out too. Not studio audio, but Audiophile level, but the same idea:
In case money is no issue and you just want to have the coolest out there (regardless of an increase in function or not), here's some gear pr0n for you to look at:
alt text http://www.jpslabs.com/images8/aluminata_xlr10.jpg
(JPS Labs Aluminata XLR Interconnect)