There is no one best of anything, including various firearms. I would suggest that you make your choices among makers of better quality firearms. Typically that would include companies such as Beretta, Colt, Smith & Wesson, Walther, and the like.
Open
Glock
Best is a relative term that has to many variables.
Best left to a gunsmith
Best left to a qualifed gunsmith
Whichever one best suits your needs.
The Kel Tec in .40 is probably your best best.
galaxy pocket of course
Best for what? Casual plinking? Hunting small game? Olympic competition? A vest pocket sized defense gun? There is no one best for every purpose. I even keep one REALLY cheap, REALLY junky .22 revolver in my fishing box- loaded with shot shells- for snakes. THAT is the right .22 for THAT use.
The daranger (not correct spelling sorry) its a small handgun that can eather fire a .45 or a .410 shotgun shell.
inch or mm
Best left to a gunsmith