Smith and Wesson

What I use:

For competition: I use primarily the M&P series pistols for production, and soon limited class in USPSA. I use a variant of this gun in IDPA matches, and will also shoot the gun in specialty matches like Bianchi and the Steel Challenge.
For carry purposes: I carry a M&P 9 C (compact 9mm) daily, and have been doing so for years. The gun has NEVER failed me, and offers a platform similar to the M&P I compete with.
I also shoot and use the M&P Rifles in all classes I teach, and have one set up as a home defense gun if I were to need some serious firepower.