Re: G19 vs M&P9
To me, I felt like asking if this is a trick question. Of course G19 over M&P9, for a better reliability, durability, longer track record, accessories, low bore axis, etc. But to each his own, others feel the same way about M&P9.
Now if you throw in a sig p228, that is also a quality pistol.
I have both glocks and sigs. They each have different pros and cons.
Glocks pros are that their durability and rust resistant are almost unmatched. They are very light with polymer frame, which is nice for carry. Glocks shoot various rounds (hollow point, etc) without problems. Cons are that they are "blocky" and depending on the holster, uncomfortable for me to carry and sometimes harder to conceal. Also no traditional safety and fairly light trigger pull. They triggers are subjective, they have an uneven give to a point before giving more resistant and firing, which some like and others don’t.
Sigs pros are their precision triggers with even smooth pull throughout, alloy heavier frame for recoil management. Their metal frames also allow for crimson trace rubber wrap around grips, which I like more then the options for polymer frame pistols because the laser point of aim does not shift with reholstering, and they feel more comfortable to grip for me. Cons are weight.
Of your choices, glock 19, sig p228, M&P9...I would choose sig p228 because sig is no longer manufacturing them anymore. Sig p228 is also a little slimmer than p229, and with rounded edges comfortable to carry in a proper holster that handles the weight well.
But then it really comes down to which one YOU shot the best.