Here, don't read anything anyone has said, I'll sum up what you should do (again):
Play them all and find out what you like the best, go in any order if you feel that it wont hinder your experience with earlier games (such as ffIII) due to the fact that as the series goes on the gameplay seems to be overshadowed by the story, but luckily Square seems to pull off something original or refreshing each go-around.
Also I played FFIII on a ROM which wasnt too bad, you can wait for the DS release, but playing the NES version seemed a bit more magical to be honest.
Also I'd stick wtih the GBA version of FFIV, although I didn't finish it, the menus are cleaned up and easy to navigate, rather than older releases which are a bit frustrating.
But seriously, everyone hates or loves each FF, and trying to get a unanimous opinion on one would take a miracle. You could expect to shake hands with Jesus before you see two people agree on this subject. Play the games with an open mind, don't let anyone corrupt your opinions about the games before you play them
How ya doing, buddy?