All hdmi cables are the same, do not be fooled by the ones that can cost up to £100 there are some brand new on amazon for well under a fiver and the reviews all say they are good quality
Also the only difference between dvi and hdmi is that hdmi carries sound
HDMI quality is all the same, but the cables arn't. Different revisions have different abilities.
The main one people care about is High Speed. If your cable length is more than 7m then a high speed HDMI cable isn't high speed any more unless its amplified.
You need a high speed cable for 3D or possibly if you intend to use a 120Mhz monitor. At least thats my understanding from the home cinema forums I visit!
DVI will also work for a 120 mz monitor, i currently run a BenQ at 120hz on supported games using DVI output (DVI-I i think), this allows me to run sound directly from my sound card into my seperate speaker system.
DVI is identical in quality to HDMI, just it lacks sound as Wozza above has noted, so long as you're using the correct version of DVI (DVI-I or DVI-D depending on what your monitor supports) or a HDMI 1.4 cable with compliant hardware/software then things will work for 3d, neither is "superior" (and for multi monitor setups, you're more likely to see dual DVI output as opposed to dual hdmi).
note that you can get adapters that combine DVI input + a Digital Audio input to output via a HDMI cable connector, i got one ( from digitaltv.com or something like that) and my laptop happily played through a widescreen tv with some resolution tweaking (due to laptop having higher resolution than the tv did!)