I most definitely won't answer the question 'what's the best', but I'll answer 'which one is my all time favorite that I recommend evaluating'. M&P 45c.
Most accurate, comfortable, fastest handgun I've ever shot, regardless of any criteria including make, model, materials, capacity, caliber, comfort or concealability. I think it does everything better than any other gun I've owned.
I carry a G29 most of the time, I guess, mostly because it's always 'there'. For familiarity, accuracy, speed and confidence, I should probably go back to carrying the M&P.