My absolute favorite gun is my Browning BAR Safari II in 30-06. I have a deal with Mr. Browning, as the rifle likes to be called. I put him in front of a deer and he knocks them down.
If I hit a deer anywhere close to right, they go down right there. Even the few I didn't hit quite right didn't go out of sight. Now that is really more due to the caliber and round I use (Federal Premium w/ 165 gr Nosler Partitions), but I give Mr. Browning a lot of credit anyway.