Is an Audioquest Forest a decent entry cable @ $35?
For about $10 more I would suggest the Supra USB cable. It has received some very good reviews in the UK and the computer audio forums. I prefer it to my Audioquest Carbon which was over 2x the cost.
FWIW, here are some USB cable ratings from Martin Colloms. (higher numbers are better)
Colloms Sound Quality Ratings: Interconnect Cables - hificritic.com
Audioquest Diamond USB 75
Audioquest Carbon USB 1.5m , 5metre 67, 35
Cardas Clear USB 47
Chord Silverplus 5m USB coiled 70, uncoiled 90
Furutech GT-2 USB 82
Kimber USB-Ag Blue 80
Kimber 'USB' 73
Supra USB 2m 70
QED Graphite USB 3m , 1m 36, 40
Wireworld Platinum Starlight USB 70