Here are my .02 on the subject...there will always be a debate over the caliber and, as I am seeing, pistol vs. revolver, so I won't go too deep into that. The simple answer, IMHO, is get what is comfortable FOR YOU. Go to the local gun store and hold several sizes and brands. An ultra concealable gun generally (for me anyway) doesn't feel great in the hand, the grip is small and its just not built for comfort. Conversely a full size might feel good your hand but its not as easy to conceal. Consider what you want to do with it and where you want to take it and go from there.
If you can, shoot a few of them too. Revolvers are great and as mentioned, very simple and reliable but they have a greater felt recoil. Same goes for different calibers, again, go with what is comfortable FOR YOU and don't worry too much about what others say. Everyone is different.
That said, I carry Glocks on and off duty and love them. Very simple, very reliable and high capacity. I don't care what anyone says, I want all the rounds I can get in one place. I would rather have them and not need them then need them and not have them. For off duty carry I don't like to carry extra mags on my person so its nice to walk out of the house with no less than 11 rounds ready to go. I like the compact version of the Glocks for day to day carry (I think its the 19 in the 9mm), pretty easy to conceal but still big enough to get a good grip on.
Good luck and be safe! :thumbsup: