Get a Ka-Bar Large Heavy Bowie. It's strong, not so heavy and not so large. If you want something you can hack and chop with, try an Ontario Marine Raider. It's big and heavy, but will fell a tree and chop fire wood with no problem. A Cold Steel Trail Master also is an astounding knife and, surprisingly, so is the Rajah II (a very strong folding knife that can be carried discreetly on your person).