I thought Dragon Warrior VII was terrible. It was too hard, and wasn't fun enough for the challenge to be enjoyable. It's also too slow to get going and the abilities and jobs weren't anything special.

Otherwise I love this series. Here's what I think:

I - Classic. Good because it is a classic, a nice quick game that has it's place and time.

II - This is my least favorite of the NES DWs. It was just kind of 'eh', for lack of a better word.

III - Best one. Selecting your party was very FFIish, and that was a great game too. I liked the class change system, it allowed for some interesting combinations and allowed you to mold your characters into whatever you wanted.

IV - The not-control-your-party was kind of annoying, but this was still a good game. I liked that the characters had personalities again and you got to see some of their background before the main story started. Taloon was so cool.

V - Just started this one and it is kind of odd, but still better than VII. After battles the monster sometimes asks to join you and that is your party. I hope I get some human players eventually but it doesn't look like it. Weird but innovative.