All of the above are good reccomendations! Rugers are inexpensive and reliable, Sigs are pretty much bulletproof and a good investment, the Glock 17 all those things. The XD is pretty much like the 17 except for the grip angle. No experience with the S&W. The CZ is about the price of the Ruger, accurate and reliable as the Sig, with ergonomics that beats them all! If you haven't handled one, by all means before you buy, get your hands on one! Everyone I know that has handled one says it sits better in the hand and points more naturally than any they have tried.
Merry Christmas and a great new year!
Savage