I love to hit with the Borg Pro, Vilas and the Maxply Fort, but my favorite so far is the Jack Kramer Autographs. The unstrung frames are a whole new feel if you're used to ones that have gone soft.
I was scared to use the Maxply Fort after my dad said he used to snap those in the throat pretty quick... But then again, he also used to have the graphite F-200s breaking on him after a couple of weeks.
String them low and they should last a long time.