I second the Intel Adapters, we've replaced a few onboard nic's in white boxed servers and had great luck with them.
If you want a cheaper solution, I've had good luck with the USRobotics gigabit network cards as well. I think for a business application, shelling out $200 for a network card should be pretty easy to do. For home, or test use, it's a bit expensive. If you're running windows, the software that comes with the NIC's is quite handy too, it's really easy for finding faults and errors on the cable or line. Chad
