Benchmade Mini Griptillian
After carrying a pocket knife / multi-tool of one kind or another nearly every day for the last 20 years this has been my all time favorite. The ergonomics on it are fantastic and it's comfortable to use and use hard. The action and mechanism on the knife are very smooth, precise, and mechanical yet don't get clogged up after years of neglect and very very very (maybe once every 2-3 years) cleaning and lubricating. The blade lock mechanism is wonderful and ambidextrous and the blade can be unlocked without your finger crossing the path of the blade making it much safer to close up.
Market price is ~$80-90 and it's worth every penny.
I've come to REALLY like Benchmade, and in particular their Blue line of knives. Very high quality mass production knives, made in Oregon.
The only thing that might be better than this is the full-size Griptillian. But then, it's a bigger knife. The Mini is perfect for everyday use . . . not too big, but big enough to give you a very good grip on the knife.