I love the choice of dialogue in the Monkey Island games. Even if you have to search to find the lines that will continue the plot/give clues/etc., it's all so funny that I don't get bored or irritated. When I replay the games, I love to go through all the choices of dialogue I can, especially in the later games (3 and 4) where you can hear Dominic Armato's adorable and hilarious Guybrush voice.
And then, for another example, in Neverwinter Nights, you have dialogue choices that all move the story along, but allow you to sort of choose your personality -- you can be rude, or kind, or whatever.
So anyway, I like dialogue choices, but I don't necessarily need them either. I'll be happy with them or without them.
On a different note, one thing I would NOT want to see in KQ9 is Rosella married to Edgar (the Four Winds seems to suggest that she and Edgar are still courting -- I was happy to see that). I like that Rosella isn't ready to settle down yet. She has her father's adventuresome sprirt

And, a few minor things I would like to see: give Valanice blue eyes (I HATED that green color in KQ7!) and please cut Edgar's hair (at least a little)
