My favorite- the smallish but dependable Dragonfly. I've carried one for over a year, and have never been in need. However, I have very light uses. I also have a Delica I tend to keep handy in a backpack or my car, but have never found need to go get it when my Dragonfly was handy.
Thus far -- own only 3 -- the Goddard Ltwt. I expect that may change soon, when I get my Wegner and Calypso Jr. Am prepared for either to become my favorite. Or not. The Goddard is lightweight, but goodsized -- I like 'em big usually -- sharp, easy to open. Do wish it was tip down, but the ambidexterity more than makes up for that.
I also like both my other Spydies, but that wasn't your question.
It's very hard to choose, but I think my favourite would be my plain edge <b>Chinese Folder </b> . I waited so long for it that I was prepared to be disappointed but I'm still knocked out by it's design and construction. Having a blade of VG10 doesn't hurt either <img src="smile.gif" width=15 height=15 align=middle>. For second place I'd be hard pressed to choose between the Military and Calypso Jr.
Clay
Don't worry that the world might end tomorrow, in Australia it's tomorrow already.
Endura - Its hardy, simple, unpretentious, solid, loveable, fits well in my large hands and affordable! <img src="wink.gif" width=15 height=15 align=middle>
I may just have to update my favorite to my new plain edged Military. Unbelievable. It's no nonsense, classy attitude are hard to resist. I am amazed at how easily it lurks in my waistband nestled just behind the right hipbone, and is forgotten about until I find a need for it. The only other knife which "lurks" better is my large Micarta Calypso; as it sits lower and feels slightly thinner. The Military though, just exudes confidence.
I'm sure leaning towards it. It's like trying to choose amongst beloved children...not a fair question at all.