There's a whole list of what is/is not legal. I think even the small Swiss army one I carry is illegal, as the way the law is written, they all could be considered illegal. The key phrase is 'without any explainable lawful purpose.' I read somewhere they tightened them up after 9/11.
My current EDC knife is a Bench Made Mini-Griptillian. 3" blade with a thumb stud (no spring assist) which is legal in NJ for assisted opening.
I have been carrying a knife of some sort nearly every day of my life since the age of about 9, just like my father did.
I carry larger fixed blades for hunting and fishing purposes but I make sure I always have a valid reason for carrying the larger stuff. I have never been questioned on my various EDC's and I have had to temporarily sign it over a few times when entering County Courthouses or municipal buildings for work purposes.
I am really surprised at how many people today
don't carry a knife. The people I work with and my family always say, "Ask Scott, he's always got a knife on him." when they have to open a box or cut something.