Well, I guess someone should speak up for the Iwill KK266. It's an exceptional board, very stable, and includes great onboard sound (which could save you $$$ on a sound card). Take a look at Anandtech's reviews and their roundup of all the KT133A series boards for more information.
In reality, you can't go wrong with either board. Buy whichever one is cheaper (probably the Iwill in this case).
Nick