I personally prefer a fixed blade, like my Bradford Guardian 3, but when I need a folder, Spydercos are hard to beat.
Great suggestions so far but I highly second and suggest a spyderco delica.
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In short, I love my delica, I'm sure you'd love one too.
My wife would second the above quote. Long, long ago, in another galaxy, we met at college in Golden, and while out on a date, I bought her her first knife at the Spyderco factory store (across the street from Mannie and Bo's, which had great calzones).
A few years ago (but a long time after that first knife), we were visiting family in Denver, and we went through Golden and hit the Spyderco Outlet. It was not in the same place we remembered, but I found a Manix2 and she found a Delica4 that she carries and uses all the time.
Its funny now that when she is out and about and someone needs to cut something, she is the only one with a knife.
I laugh every time she tells me "and then, I had to pull out my knife and save the day" or something similar. The best part is when she tells about the other folks asking where to get a knife like hers. :~)
For a folder, the Delica is a
very good option, and from my wife's experience (and my limited experience when I can steal it), I'll second it. A Delica Wharncliffe is on my short list right now. Then again, a Manix2 or a Persistence (the Manix2's backup for me) or a Dragonfly (my wife's backup blade, and an Anniversary present a few years back), are great options too.
Enjoy and good luck in your search.