What is the best NIC out there for a desktop PC?

I’m having problems with my integrated network card in my mobo, and i think it has something to do with the Win 7 64-bit driver for the card just being somehow a little wonky. installing the drivers for it from either windows, or from the manufacturer just seem to mess things up more. so what’s the best separate NIC i can buy that will fit into one of my PCI slots?