Originally posted by edesignuk
Get the 20" and 512MB RAM. If you get the 17" you will only sit there looking at it wishing you had put the money towards getting that 20" cinema. 512MB will get you by, and you can upgrade this very easily and cheaply at a later stage, you can't upgrade from a 17" to 20" quite so easily.
edit: BTW, if you do go for a 17" 'regular' ratio LCD, don't get the Apple one, they are out dated, and over priced, better can be had for less.