For folding knives, I have yet to find anything better than the Boker Plus Kalashnikov 101. Excellent blade geometry on these. The flat ground blade works really well for slicing through heavy material without getting stuck like hollowground blades tend to do. It also carries quite well despite it's size. It's slim profile and deep set pocket clip allow it to ride in the pocket very unobtrusively.
For fixed blade knives, I like the Schrade SCHF9 Extreme Survival a lot. Really good ergonomics for a field knife. You can hold it near the back of the handle for chopping, or choke up on it for more detailed work. The 1095 carbon steel blade takes and holds an edge extremely well. This thing just never seems to get dull. At the price these normally go for, you also don't feel bad putting it through some abuse. My only grip with this knife was that one of the handle screws got loose while chopping with it and fell out, lost forever I guess. I had to find a similar metric thread screw to replace it. While I was at it, I lock tited the rest of the handle screws, which I think is a good preventative measure for knives that might see some heavy use.