Somebody needs to put the criteria in here for what's best. My criteria is as follows, besides price.
1) reliability.
2) size and weight, concealability.
3) resistance to the elements.
4) ergonomics.
5) capacity.
6) sights and sight options ( lasers ) etc...
7) accuracy.
fit and finish ( cosmetics )
9) accessories available.
I have the following 9mm's.
Glock 17 and 34.
Original cz75 with no import marks, military version with baked on finish and lanyard ring. ( great gun )
Home built Caspian high cap frame with springfield armory slide 1911, ( bough coup fun to shoot )
Kahr steel k9 ( good pistol )
Springfield armory P9, a Tanfoglio in much better finish. ( good gun )
A S&W 940, 5 shot revolver ( daily carry, great gun )
All of the above function flawlessly and all of them shoot acceptably to great.
9's that I have owned and don't anymore.
Argentine highpower, worked well, but trigger jobs would not hold, you can fix that now with C&S shop parts.
Springfield p9 compact, ( wish I had that one back. )
Glock 19 and 17l, the 19 was a 3/4" gun at 25 yards, had it hybrid comped and my boss had to have it, the 17L 3 1/2", go figure, although I have always found the short glocks to shoot very well.
S&W 469, shot well, and functioned well, I just did not like the D/A, S/A transition and the safety position.
Reliability wise, all my 9's have always worked. With my build I prefer the Kahr over the Glock or anything else for holster carry concealed. In competition, my Caspian is top drawer and just plain fun, kinda like shooting a .22rf + 19 rounds + 1 in the chamber. Daily concealed is the 940 in the front pocket with 2 moon clips in the left pocket. Out in the field, the CZ is a great gun, the epoxy finish is not quite as good as the tenifer Glock finish, but touqh. My springfield p9 has a comp and I built it for my wife, with a scope mount. The Glock 17 with Crimson trace grip, and 28 round mag is the bedside gun.
Do I have a favorite? Yeah, a bunch of them for the role they are meant for.
Sorry, long winded as usual.