Baretta 96FS, .40 cal, S-A. Very accurate, easy to handle, can easily get off 2 rounds per second. The 10 cartridge clip releases very quickly which can be advantage if you need to put another clip in. I use 155 gr FMJ personal defense loads. Moderate penetration and good expansion.
Other good choices are the SIG, Para-Ordnance, Glock, H & K, Kimber.
If used for personal defense or stopping aggressive predator game you want instant stopping power...at least enough to get off a second or more shots before you become a target.
For any of above expect to pay between $600 and $1,000. However, you want reliability..."you don't get a second chance to make a first impression." :cowboy:
As others have said, with a larger calibre (minimum 9 mm) a hit anywhere on the animal will either stop or slow it down...again, enough time to squeeze off another shot.