re: Handgun for Home Defense

Crocs,
Tough to make a recommendation w/o knowing some info about you and your shooting history. Nevertheless, one can narrow the list down to just a handful using a few general recommendations.
Experienced shooter: Full size striker type semi-auto such as Glock, M&P, Sig or Springfield XD. Might also consider DA/SA semi-auto, although my personal preference is either DA semi-auto or SA semi-auto, not DA/SA. I'd suggest a gun w/o an external safety lever unless one's willing to practice sufficiently to become proficient manipulating a safety during stress. A 1911 is always a fine choice IF one is willing to learn it's manual of arms. Full size revolver is always a fine choice, as well. As far as caliber, w/ the appropriate/best loads, 45 ACP, 40 S&W, 357 Mag and 9mmm all are good for home defense. 9 mm is least expensive to practice w/ for the non-handloader. If the shooter is troubled by the recoil/muzzle blast of the 357 Mag, I'd instead look at the 38 Special w/ +P loads.
Inexperienced shooter: Full size revolver in 357 Mag w/ same exception for recoil/muzzle blast as above.

If there's the chance that multiple levels of experienced shooters may handle the gun, I'd choose the gun appropriate for the least experienced shooter. Many women have difficulties manipulating the slide on a semi-auto handgun.

Of course, the single best home defense gun is the one you've ruled out, a shotgun.