I only really have experience of swords and knives, but they both sound well suited. Shield for parry, low knockback so you can land three hit combos, huge backstab damage on the secondary. (more relevant when fighting in a team) Knives are faster with a longer lunge, swords have better overall reach.

It's really all down to what suits you personally though. A weapon whose timing matches your twitch instincts is worth more than any stats analysis and they're all viable.