I voted .357 magnum, but not because I really like it. Where I currently live, that cartridge is the right choice for the full range of my handguns, from my CCW to my trail gun. I could go buy a lever-action and use it for deer hunting if I wanted to. To boot, I can even buy/reload completely non-toxic ammo, which makes my wife happy.
I prefer .44 magnum since I can also use it as a sidearm when hiking in my home state of Alaska. But, it's overkill for the place I currently live, and why pay for .44 ammo when .357 magnum will fit the bill? Also, its less-powerful variant (.44 spl) makes for a somewhat larger CCW than one in .38.
.45 colt never appealed to me. It's too big for concealed carry, and there aren't many revolvers that can shoot it safely at +p pressures, at least not compared to .44 chamberings.