Telephone to router wire (RJ11 4 connectors) is best as short as possible unless you can get a shielded one (ours is 10m with no loss). PC to router cable (RJ45 8 connectors) can go up to 100m in theory without loss. If your device never moves I would always wire it where possible. Wireless g tops out at way less than a lot of people's Internet speeds, which leads to them thinking they're getting less than they paid for/were advertised.