For network cables, I'd suggest that bluejean cables certainly deserves to be in the conversation. Many at computeraudiophile recommended them to me, and I've been happy with their ethernet cables. Cheers,
Blue Jeans for the ethernet cable and Oyaide for the USB.
Other sensible priced USB cables are from Supra, Straightwire, Audio Sensibility and even Wireworld up to Starlight.
I'll 2nd jackd's Oyaide neo d+ Class A nomination.
What I heard when switching to the Oyaide from entry level USBs by Audioquest (Pearl) and Pangea AG (all silver) was simply "more".
Note too great deals right now on the Shunyata Venom USB at Music Direct and The Cable Co.
The DH Labs Mirage USB is something else to consider.
Can't help on ethernet cable options.
After reading suggestions here and in Ozzy's recent USB cable topic I got Oyaide neo D+ Class A USB cables today. A clearly better sounding cable than a standard computer USB cable. A good value.
I've read good things on Ozzy's topic about Acoustic BBQ cables made by a gentleman here on Audiogon ~$150.00. And Curious Cables from Austraila ~$350.00. Curious offers a no questions asked return policy speaks well of their product IMO.