People who start these kind of threads are always the subject of ridicule, but I think people underestimate our capacity to defend ourselves against wild animals. Humans are not these creatures usual prey, and any kind of resistance will make them think twice, let alone a deep stab wound. You hear many many stories about people who defended themselves against wild animals with less than a knife, so yeah, I'd rather have a knife than nothing in the type of scenario that the OP is talking about. To answer the question though, any knife that is pointy will do, a Kabar USMC would probably be as good as anything else as well as offering you a fair bit of value as a utility knife.
