Cold Steel Bushman

The Cold Steel Bushman is one of the best low-end survival knives. Made from one piece of steel, without any joint between blade and handle, it is many times stronger than the typical flea market hollow-handled survival knife. It's designed to easily transform into a spear.

There's a decent video on YouTube that shows it in action.

Gerber LMF

I found this excellent Squidoo lens all about different models of the Gerber LMF II, a very solid military-issue knife. It's a smaller, under four inch, blade, but it's full-tang and a good steel (12C27 stainless). Various different models come plain-edged or partially serrated, and with different sheath options.