Haven't posted before but I read this site every day.
If you like Savatage with Jon Oliva then definitely check out Hall of the Mountain King and Gutter Ballet. To me the highpoints of the Zak era are Wake of Magellan and Edge of Thorns.
Streets is a great album but is an acquired taste in my opinion because it is a bit cheesy but give it a chance as I, too, believe it was a high point for the band.
I had the pleasure of being in my teens when they played opening for Testament with Pantera as the opener (Cowboys from Hell tour before anyone knew who they were).
Savatage was excellent and sadly I never got to see them again so I am glad I was there.