As everyone knows, I don't like liner locks, and no liner lock will make it into my "top locking folder" list.
I do like the axis lock, integral locks, and some lockbacks. I haven't had enough time to play with a rolling lock, but I anticipate I'll put that up on the list as well.
My fave folders?
Benchmade Axis, for the lock technology, *incredible* comfortable ergonomics, and absolutely superb performance. This is my #1 folder, period, right now.
Sebenza. Speaks for itself. And I don't even own one yet! But having handled many of them at shows and cutting with my friends' Sebenzas, it's clear why this knife generates such strong feelings.
Benchmade Pinnacle. Ergonomic, great integral-style lock, great performance.
Steve Mullin Pack River folder. A lockback with a 440V flat ground drop point blade, excellent strong lock that won't accidently unlock on me, nice ergonomics, stunning aesthetics. Production-quality wise and design-wise, for the "Sebenza" of lockbacks, this is it.
Staying with lockbacks, I feel the micarta Calypso Jr. is the best knife Spyderco has ever designed, and one of the best values to be had in a knife overall, period. Great looks, incredible performance, nicely done ergonomics. The perfect gentleman's scalpel.
In the realm of more bang for your buck, the delica and endura are the last word for me.