I would have liked to see Xon and Illia and some of the planned episodes. Judging from the script in the Phase II book, the Phase II version of The Child would have been a lot better than the TNG one.
Yeah, but I thought the concept for Devil's Due was worse, so it balances out.
I liked TWOK-TSFS-TVH trilogy. That allowed us to get TNG and following spinoffs. If Phase II had been born, I don't think we would have seen anything else afterwards, which would be a shame.