I think Romero just lucked out with Dawn. Dawn was a great mvie because it's almost on the same level of fantasy as Red Dawn. Wishing you could be in that situation so you could see what you're made of. The fact that the people do what a lot of people dream of --moving into a mall and loading up on guns-- made it even better. The effects were kinda cheesey, but I guess they were tops for their time.
Day, for the most part sucked, but the gore and zombie make-up effects were incredible and that's the main reason I loved it.
I never liked NOTLD. I didn't think Creepshow was all that special... and IIRC Romero wasn't the "father of zombie movies". There were others before his, he just made one that happened to go so mainstream he got all the credit for the genre.
Land of the Dead... it blew ass.