For me, it's the fixed blade and the saw. I carry a Becker BK-2 that's plenty heavy and thick enough for chopping and splitting, and a Silky Super Accel saw with an eight inch blade -- a pretty good combo, IMHO.
Given my druthers, however, I'd carry a small hatchet, too. A lot of this would be dependent on the type of terrain your going into. I would think that the requirements would be a lot different in the North Woods than they are here in Southern California. Around here, a knife and saw works well. Where you are, things might be different.