As for wired network, then just about everything you find on 100mbit speed is ok. Then only difference tests have shown, is related to cpu usage. But the difference here is still small.
Personaly I've never had problem with either known nic's, generic ones or onboard ones.
As for wireless, it's a different story. Stuff don't have to talk together.. Argh! Yes, I tried to set up a wireless network, but after bad speeds, dropped connections and a lot of anger, I got back to good solid things. Wires that is!
Oh, anyone reading this has good options for gigabit cards? Gonna wire up my entire house this summer, so research is a long process.. I'll have a server with RAID1+0 for safety and speed over a gigabit network where everything will be stored. But I need some input on ok nic's..