There are multiple ways to avoid having onion-tears and I don't think the knife that you'll use matters... but well you asked for a knife and I can suggest the MAC professional Chef's knife and it has good reviews, lightweight and like all good knives it is made in Japan. It costs less than $150 which is a bit steep but the quality of the cut and durability is ensured. Just a quick tip, chill your onions or place a wet paper towel on your chopping board to avoid onion tears.
