That question is really too broad as stated to really answer. What will it be used for? Personal defense, hunting, or both? If it's for defense, will it be a house gun or concealed carry? If it's for hunting, what will the game be?

Being a military veteran and gun nut I have handled and used many. Handguns are one of my favorites. These are the ones I would or have picked for each.

I probably have more experience with defensive pistols than any other. I have oned several and used many more. 1911s remain my all time favorite for a strictly defensive pistol. They just fit my hands like the were custome made for me. They are plenty powerful, and parts and accessories are plentiful. they can range in accuracy from average to downright amazing. My carry gun of choice right now is a Springfield Micro Compact with a 3" barrel. In the near future though I am going to fit it with a 4" barrel and slide because of the better velocity/ballistics and leather is easier to find for the 4" barrel.

If it's going to be a house gun then I would (and presently have) a full size 1911. Both my carry gun and my house gun are fitted with Novak night sights.

If it's going to be a hunting gun then a Ruger, Taurus, or Freedom Arms in .44 magnum will do just about anything you can reasonably ask of it short of moose, elk, and dangerous game thoug it has taken many of them as well. If any of those animals are on the menu i would upgrade to the .480 Ruger or .454 Casull. If you're really a masochist then get a .500 S&W Magnum.

If it's going to serve dual duty as a defensive gun as well as a hunting arm then I would go with th .44mag. Another option would to get a 1911 (full size) and get a .460 Rowland conversion. This will allow you to use the grips that you are familiar with and the .460 Rowland at (least on paper) practically duplicates the .44 magnum ballistically. Downside is that the conversion (which is drop-in for everything but a Para-Ordinance 1911) costs about $350. You can buy a .44 mag for about the same price.

Decide (rather tell your friend to decide) what it will be used for then go from there. Go to several dealers and handle as many as you can. Shoot as many of them as you can BEFORE buying. Then, buy the one that feels right.