I honestly go to gun shows and tend to stick with bayonets when I want to use knives. My favorite box opening knife is an M1 Garand bayonet. A lot of these old bayonets work really well as repurposed "around the house" knives. Plus they have collector value in case you need to get rid of it. And let's be honest, there is nothing cooler than using a M1 bayonet to open boxes on Christmas. Just be careful. It's easy to cut yourself with any knife and I've done it multiple times.