Firearms and especially handguns are very dependent on their operators. What works for me may not work for you, the suggestions of trying a bunch of different models and calibers are the best suggestions in this thread IMO. I have shot everything that has been suggested in this thread with the exception of the M&P. I have owned Glocks, S&W revolvers (really regret trading away my 686 .357mag), and several other semi-auto pistols. I understand the love Glock owners have for their pistols, they are accurate and durable and relatively inexpensive. For me, they are clunky and I don't like how it fits in my hand and have yet to find a striker fired pistol with a trigger that feels really good to me, but the XD is very nice. I recently replaced my home defense pistol because I also wanted something that could easily be concealed, I wanted a hammer fired pistol, and I wanted it to have a manual safety as I have children in my home. I did hours and hours of research and the EAA Witness (CZ clone) kept popping up in reviews based on my criteria. I picked up the full sized version in .40S&W with a 4.5" barrel and despite it's size it is pretty slim and conceals very well with shirts that are just a little baggy. I have only had it out to the range once and put a few hundred various types of rounds through it and am extremely please with it, especially for a brand new pistol that was only $400 out the door. The trigger is very smooth and doesn't have a mile of travel when cocked and has a crisp reset.
Just try a lot of different models that have the features that are important to you before you buy so you aren't trying to sell or trade for something different if you aren't a fan of what you originally purchase.