ESEE-4 - great knife, great sheath, and if the budget will stretch, look into the TKC handles.
I personally was really disappointed with the BK-16 (hated the ergos and the blade shape, but that's just me) but a lot of people love it and I have other Beckers that I would swear by.
Keep an eye on the Exchange here too as good knives can come up with very good prices. Around your $100 mark you could check out a Bark River Bravo or Aurora (I have one and love it), or a Fallkniven F1 or S1.