You'll get as many opinions as there are knives in the catalog. It really depends on your EDC use and what you prefer out of that. I tend to cut a lot of heavy cardboard, so I need a knife that slices well and has good ergos. I like wharnies for this purpose so I'm a big fan of the Yojimbo 2. Lately i've been carrying a DLC Manix 2, and love it. The blade has a shallow enough belly that it cuts almost as well as a wharnie but is also more versatile at other tasks like food prep. I also HAVE to carry a lock that is easy to operate. I'm familiar with pretty much every lock design out there, but I really prefer one that I can drop the blade shut in one fluid motion without having to manually move the blade, like you do with a back lock or liner lock. This is where the CBBL lock and compression locks take the win for me.
Something else I spend a lot of time mulling over is what I like to call the "circle of movement" required to open the blade. On some knives (Like the Native), the thumb hole is further down towards the middle of the blade, which puts it further away from the pivot, which makes that circle of movement larger in diameter, which for me is a downer. By comparison, a Para 2 or Vollatton are much closer to the pivot, and snap open much easier because of it. This might not sound like a big deal and most people never even consider it, but if you think about it and handle several knives to feel the difference, you'll never be able to overlook it again. It's as important to me as the ergonomics.