Best gigabit network interface for FreeBSD?

[Brett Glass]

Was going to post this to net@, but figured I'd get a bigger 
audience and better answers on this list. (Please copy responses to 
me as well as the list to make sure I see them.)

I'm building a machine which is going to have very high network 
loads, but can't really use a TCP/IP "accelerator" because much of 
the traffic won't be TCP. What, as of now, is the most capable 
gigabit Ethernet interface for FreeBSD? Which has the cleanest, 
simplest driver? The most onboard buffer space to prevent overruns 
and underruns? The fastest bus interface? The least interrupt 
overhead (important because interrupts in FreeBSD 6.x are 
relatively expensive)? I have some Intel "em" interfaces available 
to me, but have been told that while the driver is well supported 
they are quirky and not the best choice.

--Brett Glass