Since WWII has there been a better designed "Fighting " knife then the British Fairbairm-Sykes Commando Knife/Dagger ?
Randall no1. Would be my choice.
I'mRandall no1. Would be my choicehttp ://www.randallknives.com/wp-content/uploads/2012/06/model-1_03.png
Make sure you get one with a Micarta handle.
Here's mine.
Glock field knife. It's a bayonet, but sharp and tough. Inexpensive with a useable sheath. Lots of good reviews out there.