If a .45ACP is an option, check out the Para-Ordnance LDA Carry Safe line. http://www.paraord.com/pages/carry.html

I like Beretta .380s, if you feel comfortable with that caliber for personal defense. I think it's reasonably potent and probably easier to manage controllable double-taps and followup shots, but YMMV.

Otherwise, HKs, Glocks, Sigs...you really won't go wrong.

"Think of it, if you like, as a librarian with a G-string under the tweed." Clarkson on the Mondeo.