They all perform about the same...
I actually went with the ECS sis 755-a2 board...I know, I know, ECS...BUT, my old ECS SIS735 board served me well..
This one is prett zippy...the IDE performance is nice

games run the same as the other boardsin the 754 range...the only thing it lacks is Firewire.
If you don't like ECS, Asrock makes a 755 board. I suggest you look into them.
I tried the kt800 and nforce 3 boards.
both are equally nice.
Nforce 3 has the built in firewall and some of the boards have giga lan...
you know, in the end, it really doesn't matter

just pick featrues you like.