I believe the OP is asking opinions for a twin to have fun with, not for a serious twin.
The most fun twin I flew was a Baron 55 as it oozed character , had great handing, was relatively good on fuel but I do have a problem with having fun with
Ok if you have money to burn having fun means just that but I am more into determing a mission profile and choosing an aircraft best suited to that mission profile.
Suppose having fun with could be a mission profile but apart from having fun syncing the engines and that glorious sound of humming engines what is the extra fun of flying a twin ?
Pace