If in survival u mean SHTF, Just have to visualize what the use of the knife will be..for me the biggest danger is too many desperate people in the confines of the city..so id have to get away.but if u stay the knife will be a back up to your gun, hopefuly and may be used for dressing game aka fido and kitty and tweety..The military will probably move in and declare martial law and take away ur weapons...yep..id definately bug out to a friend or relative in the country. or just take up Teepee living.Just have to invision what youd want to have with you at any one time under various situations..there is no best. A Sak, multitool, Rat, or whatever will serve u well for most situations.