I recently broke stupidly my camping knife and had to purchase a new one. I am very satisfied with my purchase, so I'll list my priorities at the time of the purchase.
Functions(sorted by priority, 1 means most important):
1. Table knife, fork, spoon (yup, you can eat soup with a knife ;p)
2. Axe - heavy blade, that can cut down a branch the size of my arm in under 10 minutes
3. Utility knife - cut ropes, shrub, band-aids, carve with it ...
4. Hammer
5. Defense - dogs, people
From those, derive required qualities (also sorted):
1. Cheap - no more than $10 - I don't want to cry every time that I abuse it
2. Sharp steel - I do not dig steels, but on cheap knifes I have basically seen two types of steel - (a)soft shiny smooth not holding edge ever and (b) hard, sharp, fragile susceptible to rust with straight parallel notches(from the grinding wheel). Needless to say, I look for (b).
3. Full-tang
4. Sturdy pommel - for hammering
5. Sold with a sheath - so that it can be carried easily and safely on a belt or in the backpack (or, as my girlfriend discovered - very conveniently tied to the shoulder strap of the backpack).
6. Plain - if I am going to abuse it, I am going to resharpen it often. I hate sharpening serrations.
7. Heavy - for chopping. Furthermore, this makes the knife able to withstand abuse
8. Cool looking (yeah ;P)
Maybe add a picture when I get home.