3" - BenchMade Mini Griptilian or Spyderco FRN Delica (I have/had both)
4" - BenchMade Griptilian or Spyderco FRN Endura
The Spyderco Delica in VG-10 was my first quality knife and it came VERY sharp from the factory. In fact, I even cut myself accidently without knowing until I saw the blood. It's got a very thin profile so it disapears in your pocket after being clipped and is pretty lightweight. Opening and closing action is smooth and the Spydie Hole is a very nice design. I can open it with my thumb over 50 times without getting sore.
I got to handle the Mini Griptilian (556) for a few days and I really liked the AXIS lock. Thumb stud with small for me so I usually opened by pulling the lock back and lightly flip the blade out. Edge came sharp, but not nearly as sharp as the Delica. I think the same can be said for the rest of the Benchmades vs Spyderco, but thats the only one ive owned so take it for what its worth. A visit to a sharpener will fix that problem.
I think the main difference in choosing between both is the price. Delica is $40-$45 while the Mini Grip is about $10 more. Customer service from both companies are excellent and they stand behind their products (from what ive read). If I were to buy again, id probably get the Delica or an Endura because of the thin profile and blade material. HTH
If interested, I have a Delica up for sale.