The Beech Duchess, Piper Seminole and Grumman Cougar were all designed, I understand, for the same competition (USAF or US Army, I think). The winner was the Duchess, the Cougar came second and the Seminole came last. That would suggest which is best.
Of all these I have only flown the PA-44, though I am assured by those as fly them the Beech 76 is better. The Seminole struggles to keep airborne on one engine, a problem the Duchess is said not to have. With anti-balance tabs the Seminole is also very nose-heavy on landing, needs a powerful, two-handed pull unless you keep some power on.
However Tinstaafl is right, school is more important than machine. I was very happy with my training (the school no longer exists).