The best could imply many different things. You've identified that your not going to overclock so you don't care how much options the mother offers for overclocking. If the best means the fastest then your going to have to get a i850e motherboard. Currently the choices are the Asus P4T533 and the P4T533-C or Gigabyte 8IHXP (I just installed this board. A lot of features...nice!). If the best means stability you can't go wrong with an intel motherboard. However I don't if any officially support PC1066 or higher ram.
Good Luck!