It's hard to beat the patented AXIS lock from Benchmade -- it's definitely one of our favorite mechanisms. Once it's engaged, the blade's tang wedges solidly between a a beefy stop pin and the AXIS bar. Plus, the mechanism is also ambidextrous and lets us "flick" the blade open and closed.
Now to be clear, we never put a locking folder to work without first acknowledging that it's still a folding knife -- or, as fixed-blade aficionados like to say, "a knife that's pre-broken in the middle." No mechanism is perfect, and a folder will never match the strength of a fixed blade.
Still, if a folding knife is the right tool for the job (or when that's what we happen to have at the time), the Benchmade AXIS has our confidence.