Here are my picks:
Under $50: Endura, Centofante III, Native (S30v).
$50-$100:
D'Allara drop point
Over $100:
Chinook, Military
Out of these, I think the best value is the Centofante III and the D'Allara. In another thread the D'Allara was referred as the "poor mans Manix". You could also make the case that the Centofante III is the "poor mans Ocelot". Then again when I think Spyderco, I think value.